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Article

MoS2/MgAl-LDH Composites for the Photodegradation of Rhodamine B Dye

by
Jingjing Dai
1,
Guofei Li
1,
Yuanyuan Wang
1,
Cancan Zhang
1,
Hui Nan
2 and
Guijun Yang
1,*
1
College of Chemical Engineering, Qinghai University, Xining 810016, China
2
College of Mechanical Engineering, Qinghai University, Xining 810016, China
*
Author to whom correspondence should be addressed.
Inorganics 2025, 13(3), 88; https://doi.org/10.3390/inorganics13030088
Submission received: 2 January 2025 / Revised: 12 March 2025 / Accepted: 12 March 2025 / Published: 17 March 2025
(This article belongs to the Special Issue Photoelectric Research in Advanced Energy Materials)
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Abstract

:
During the process of producing potassium fertilizer from salt lake resources, a large amount of waste liquid brine, rich in raw materials such as magnesium chloride, is generated. In this work, a MoS2/MgAl-LDH composite material was constructed using the secondary hydrothermal technique. Characterizations including X-ray diffractometer (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) confirmed the distribution of MoS2 nanosheets on the surface of MgAl-LDH. Under full-spectrum irradiation, the degradation efficiency of Rhodamine B reached 85.5%, which was 69.2% higher than that of MgAl-LDH alone. The results from the electrochemical, UV-Vis, and XPS-VB tests indicate that the internal electric field accelerated the separation and transportation of charge carriers between MoS2 and MgAl-LDH. These findings demonstrate the great potential of MoS2/MgAl-LDH as a photocatalyst in the degradation of organic dyes, which will aid in the green recycling utilization of magnesium resources from salt lake by-products.

Graphical Abstract

1. Introduction

With the rapid development of the global economy and the constant growth of the population, the problems of global energy shortage and environmental degradation are becoming increasingly urgent [1,2]. Wastewater includes numerous complex and hazardous organic compounds with high chroma, which easily accumulate in organisms and are difficult to properly biodegrade [3]. How to efficiently, quickly, and environmentally handle persistent organic pollutants, minimize their environmental and biological risks, protect the environment, and safeguard health, is at the forefront of worldwide study domains [4]. Photocatalytic processes that transform solar energy into chemical energy have gained extensive interest recent [5,6,7]. Photocatalytic wastewater degradation employs sunlight as an energy source, without the need for additional chemical reagents, allowing for green and sustainable development. It is a low-cost, high-efficiency, widely applicable, and environmentally friendly degradation technology [8,9,10,11]. The catalyst generates electron– hole pairs when exposed to sunlight, the active substance is produced as a result of the ongoing reaction, and the REDOX reaction occurs after contact with the organic pollutants, followed by decomposition into carbon dioxide and water; therefore, the organic pollutants in the water body are effectively removed [12]. Currently, photocatalysis technology provides an efficient environmental protection method to handle the problem of wastewater treatment.
Hydrotalcite has received a great deal of interest because of its unusual molecular layered structure; rich content; and changeable features like thickness, short electron and hole diffusion paths, and numerous surface imperfections that enhance reactant adsorption [13,14,15,16]. There are still significant limitations to hydrotalcite materials in photocatalysis, such as insufficient electron–hole separation efficiency and a narrow absorption range for sunlight [17,18]. When a single hydrotalcite material is coupled with additional semiconductors to form a heterostructure, the separation of photogenerated electron–hole pairs is enhanced, resulting in a corresponding improvement in the field of photoelectrochemistry [19,20,21]. Wu et al. [22] confined microscopic BiWO (BWO) nanosheets to the CoAl-LDH (LDH) surface, resulting in BWO/LDH S-type heterojunctions with a significant internal electric field due to the spatial confinement effect. The addition of BWO broadens the spectrum of light absorption, efficiently facilitates the separation of photogenerated charge, and significantly increases the photocatalytic REDOX activity of LDH. Perfect BWO/LDH has a removal effectiveness of 85.1% in the Cr (VI) reaction and 92.1% in MB degradation, with reaction rates 2.0 and 1.5 times that of LDH in visible light, respectively. Sun et al. [23] used a simple mechanochemical approach to effectively manufacture a CdIn2S4/ZnAl-LDH composite material with a Z-type heterojunction, as well as to degrade isopropyl xanthate sodium (SIPX), a common organic pollutant in flotation effluent. The results indicate that when compared to pure ZnAl-LDH and pure CdIn2S4, the degradation efficiency of CdIn2S4/LDH composites for SIPX was greatly increased under visible light, and was 13.4 times and 3.0 times that of original LDH and pure CdIn2S4, respectively.
Salt lake resources are plentiful in China, so recycling waste magnesium resources is critical. The basic starting point is to efficiently utilize magnesium resources to create magnesium-based functional materials with good characteristics and high added value [24]. Liu et al. [25] composited a photocatalyst with spherical CoSx and layered MgAl-LDH nanosheets that produces 262.5 μmol of hydrogen, much higher than MgAl-LDH and CoSx alone. The combination of the two enhanced the separation of photogenerated electrons and holes, demonstrating the composite catalyst’s hydrogen-generation impact. The electrostatic self-assembly approach produced a composite photocatalyst comprising MgAl-LDH and g-C3N4 nanosheets, which outperformed pure g-C3N4 nanosheets in terms of MO adsorption and photocatalytic degradation. As the MgAl-LDH concentration grew, so did the adsorption rate and removal of MO by MCN-X composites, which thereafter gradually reduced. The increased specific surface area, reduction in the band gap, and improved separation and migration of photogenerated carriers all contributed to the composite photocatalyst’s improved performance. Jihao et al. [26] initially synthesized MgAl-LDH using the co-precipitation technique, and then created Cu2O using the impregnation method while loading it onto the previously synthesized MgAl-LDH to correct the two’s differing weight ratios. The results revealed that methylene blue (MB) was chosen as the target degradation material. The degradation rate of the Cu2O/MgAl-LDH combination was 86.2%, and it remained above 80% after two catalytic cycle tests. Furthermore, the MgAl-LDH interlayer arrangement introduces the active site while preventing Cu2O agglomeration.
Among many semiconductors, MoS2 has a large specific surface area and a narrow band gap, as well as the ability to expose a large number of photocatalytic active sites on the surface, resulting in high photocatalytic reaction activity and performance that is superior to that of certain conventional catalysts [27,28,29]. Liu XY et al. [17]. effectively synthesized an S-type heteronode MoS2/NiAl-LDH that was comparable to nanoflowers. After 5 h of visible light irradiation, the composite catalyst had reached 229.5 μmol, which is much higher than NiAl-LDH. CuFe-LDH/MoS2 composites were manufactured using a self-assembly chemical approach and an in situ hydrothermal method, and the heterojunction structure efficiently reduced photogenerated charge recombination while improving quick charge transfer and utilization [30]. The DFT simulation further demonstrates that the synergistic impact of the CuFe-LDH/MoS2 interface improves the thermodynamics and kinetics of the rate-determining stage of the hydrogen evolution process. Zheng G Y et al. [31] effectively loaded MoS2 nanoparticles in MgAl-LDH using two hydrothermal techniques, and the catalyst demonstrated good photocatalytic activity for the breakdown of methyl orange dye (MO) under visible light. In conclusion, MgAl-LDH has an excellent layered structure and stability, making it a suitable matrix material. The use of MgAl-LDH can not only provide stable support for MoS2 but also prevents agglomeration or deactivation during the photocatalysis process, which can effectively improve the photocatalytic activity of the composite.
In this experiment, MoS2 was loaded onto MgAl-LDH using two hydrothermal procedures. On the one hand, MoS2 as a cocatalyst can contribute more active sites; on the other hand, as a composite material carrier, MgAl-LDH has a large layer size that can provide good support for MoS2, and the combination of the two can significantly improve the composite’s overall photocatalytic performance. Furthermore, Mg (NO3)2·6H2O is now the most commonly used raw material in the relevant literature. In this study, MgCl2·6H2O was primarily employed as a raw material to build the groundwork for the appropriate utilization of by-product magnesium resources in future salt lakes.

2. Results and Discussion

The XRD patterns of the MgAl-LDH sample and MoS2/MgAl-LDH composite sample synthesized in this experiment are shown in Figure 1. In the diffraction pattern of MgAl-LDH, the crystal planes of (003) (006) (012), and (015) can be assigned to 11.34° 22.84° 34.74° and 39.13° (JPCDS No.35-0965). This indicates that the MgAL-LDH was generated successfully [32]. In the diffraction pattern of MoS2/MgAl-LDH, the diffraction peaks of 2θ at 14.20° and 33.99° correspond to the diffraction peaks of the (002) and (012) crystal faces of pure phase MoS2 (JPCDS No.75-1539), indicating that the MoS2 phase was successfully formed in the product [33]. In addition, the diffraction pattern of MoS2/MgAl-LDH at 2θ of 11.63° and 23.38° corresponds to the (003) and (006) crystal faces of MgAl-LDH. Compared with the diffraction pattern of pure-phase MgAl-LDH, it can be found that the diffraction peaks attributed to the MgAl-LDH (003) and (006) crystal planes of MoS2/MgAl-LDH were shifted to a higher angle. This was due to the interaction between MoS2 and MgAl-LDH when they were loaded on it, which caused the overall internal structure of the composite substance to be subjected to compressive strain, resulting in the contraction of the lattice, the reduction in the lattice constant, and the shift in the diffraction peak to a higher angle [34].
The surface morphology of the MgAl-LDH and MoS2/MgAl-LDH samples under microscopic conditions was analyzed by SEM. From Figure 2a, it can be intuitively observed that the MgAl-LDH sample prepared in this experiment has a typical lamellar structure and good dispersion properties. It can be observed from Figure 2b that in the synthesized MoS2/MgAl-LDH composite sample, MgAl-LDH was successfully loaded with MoS2 nanosheets, MgAl-LDH still maintained a large sheet structure, and MoS2 was relatively dispersed in MgAl-LDH. The EDS analysis of the MoS2/MgAl-LDH composite samples is shown in Figure 2c–f, and the results show that the composite samples contained Mg, Al, Mo, and S elements. The successful loading of MoS2 nanosheets on MgAl-LDH was again verified.
The XPS analysis of MoS2/MgAl-LDH and MgAl-LDH is shown in Figure 3. A complete spectrum comparison of MgAl-LDH and MoS2/MgAl-LDH reveals that characteristic peaks Mo and S exist in MoS2/MgAl-LDH but not in MgAl-LDH, suggesting that MoS2 was effectively loaded on MgAl-LDH, which is compatible with the XRD and SEM results. As shown in Figure 3d, the fine spectra of Mg 1s were analyzed in MoS2/MgAl-LDH and MgAl-LDH, and it was found that the binding energy of the characteristic peak of Mg 1s decreased after MoS2 was loaded. This indicates that there was electron transfer between MoS2 and MgAl-LDH [35,36]. Figure 3c contains three characteristic peaks of 225.6 eV, 228.3 eV, and 213.8 eV, corresponding to the binding energy of S 2s, Mo 3d5/2, and Mo 3d3/2, respectively, among which 228.3 eV and 213.8 eV belong to Mo4+ [37,38]. As shown in Figure 3d, the figure contains three characteristic peaks of 161 eV, 163 eV, and 168 eV, corresponding to the binding energies of S 2p3/2 and S 3p1/2, respectively. The characteristic peak at 168 eV indicates that there is a bridged molybdenum disulfide ligand in the sample [39].
To find out the optimal loading capacity of MoS2, MoS2/MgAl-LDH composites loaded with different MoS2 contents were added to a 30 mg catalyst for photocatalytic degradation in Rhodamine B solution with pH = 3 and a solution concentration of 10 mg·L−1. From Figure 4, it is observed that the composites loaded with different amounts of MoS2 had a great influence on the catalytic performance of Rhodamine B. The degradation effect of MoS2/MgAl-LDH-2 (keeping the proportion of MgCl2·6H2O and AlCl3·6H2O unchanged, adding 0.1 mol of NaMoO4·2H2O) was the best, and the degradation rate reached 85.5% under 240 min of xenon lamp illumination. The degradation rate of the pure MgAl-LDH was only 16.3%. The degradation rate of MoS2/MgAl-LDH-1 (adding 0.05 mol NaMoO4·2H2O) was 43.1%. The degradation rate of MoS2/MgAl-LDH-3 (adding 0.015 mol NaMoO4·2H2O) was 80.5%. Compared with the pure phase MgAl-LDH, the photocatalytic activity of the three compounds was significantly improved.
The kinetic analysis is shown in Figure 4c, and the specific values are shown in Table 1. In the degradation of Rhodamine B at different pH values, the linear regression coefficient R2 is high, indicating that the photocatalytic reaction has a good overlap with the pseudo-first-order kinetic model. The MoS2/MgAl-LDH-2 composite sample has the highest Kobs value of the time catalytic reaction rate constant, which indicates that the photocatalytic degradation effect of the composite material is the best under the load of MoS2. As shown in Figure 4d, the photocatalytic performance of the MoS2/MgAl-LDH-2 composite sample changed little after four photocatalytic cycles, indicating that the catalyst has excellent stability.
It can be seen from Figure 5a that the light absorption range of MgAl-LDH is mainly concentrated in the ultraviolet region. After loading MoS2, which absorbs the full spectrum of sunlight, the light absorption range of the MoS2/MgAl-LDH composite is concentrated in the visible region. This shows that the load can significantly improve the absorption range of the composite material. As shown in Figure 5b–d, the obtained test data were processed to obtain the bandgap widths of different samples [40]. Compared to MgAl-LDH alone, the band gap was 5.01 eV; the lower the MoS2 load, the narrower the band gap of the sample. The band gap in MoS2/MgAl-LDH-2 was 1.88 eV. The lower the bandgap width, the greater the material’s light absorption capacity, demonstrating that the composite material’s absorption range after loading MoS2 progressively extends and may be extended to the visible light area [41].
Figure 6a shows the electrochemical impedance spectroscopy (EIS) of the MgAl-LDH and MoS2/MgAl-LDH samples containing different MoS2. It can be intuitively found that the EIS curvature radius of the MoS2/MgAl-LDH composites was smaller than MgAl-LDH. Among them, MoS2/MgAl-LHD-2 has the smallest EIS curvature radius. The radius of the EIS curvature of MoS2/MgAl-LDH-1 and MoS2/MgAl-LDH-3 are greater than of other samples. This indicates that growing MoS2 nanosheets in situ can promote electron transport to a certain extent, which is conducive to accelerating the separation of photogenerated electron–hole pairs [42]. Figure 6b shows the photocurrent tests performed on both MgAl-LDH and MoS2/MgAl-LDH. MoS2/MgAl-LDH has a higher photocurrent intensity than MgAl-LDH. These results indicate that MoS2/MgAl-LDH is favorable for photogenic carrier separation and can effectively improve the overall catalytic performance of MoS2/MgAl-LDH composites [43].
Through the Mott-Schottky test, it can be seen from Figure 6c,d that both MgAl-LDH and MoS2 are N-type semiconductors, and that the flat-band potentials are −0.49 eV and −0.23 eV, respectively [44]. Through research, it was found that the flat-band potential of the intrinsic semiconductor was the conduction band edge (CB), and the band gap MgAl-LDH and MoS2 can be obtained by calculation as 5.01 eV and 1.42 eV, respectively, as shown in Table 2. Therefore, the valence band (VB) potentials of MgAl-LDH and MoS2 are 4.52 eV and 1.19 eV, respectively. The conduction band and valence band potential of MgAl-LDH are higher than for MoS2. The band structure of MoS2 and MgAl-LDH were calculated by combining their band gaps, Table 2 displays specific statistics. The distance between the valence band and the Fermi level (Ef) was calculated using XPS-VB to further the electron transport between MoS2 and MgAl-LDH, as illustrated in Figure 6e,f [45].
In summary, the band structures of MoS2 and MgAl-LDH were obtained using the foregoing characterization, as seen in Figure 7a. When the two come into contact due to differences in Fermi levels, electrons are transported from the surface of MgAl-LDH to the surface of MoS2 until the Fermi levels of the two are equal. The process of electron transfer causes a potential imbalance between the two, resulting in a potential difference and the formation of an internal electric field from positive to negative charge, as shown in Figure 7b. As a result, the valence and conduction bands of MgAl-LDH bend downward, whereas those of MoS2 bend upward. Under light, the internal electric field promotes the separation and transmission of photogenerated electron–hole pairs, as well as the sample’s catalytic activity, as shown in Figure 7c.

3. Materials and Methods

The agents used in the synthesis of the photocatalysts include the following: aluminum trichloride (AlCl3·6H2O), magnesium chloride (MgCl2·6H2O), ethanol (C2H6O), and Rhodamine Bare purchased from Tianjin Obo Kai Chemical Co., Ltd. (Tianjin, China). Sodium molybdate dihydrate (NaMoO4·2H2O) was purchased from Tianjin Fengboat Chemical reagent Technology Co., Ltd. (Tianjin, China). Sodium hydroxide (NaOH) was purchased from Tianjin Best Chemical Co., Ltd. (Tianjin, China). Thiourea (CH4N2S) and anhydrous sodium sulfate (Na2SO4) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. (Shanghai, China).

3.1. Preparation of Photocatalysts

Preparation of MgAl-LDH [46]: Add 50 mL of deionized water, weigh 3.6594 g of MgCl2·6H2O and 2.1729 g of AlCl3·6H2O, and set up as liquid A. To make liquid B, weigh 2.516 g of NaOH and then add 25 mL of deionized water. Add the above-configured liquid B gradually to liquid A, stirring constantly at 60 °C until it dissolves fully and keeping the pH at 10 throughout. Then, put the mixture into a 100 mL hydrothermal kettle and let it react for 10 h at 140 °C. The hydrothermal product was washed, pumped, and filtered before vacuum freeze-drying for 10 h to provide the MgAl-LDH. MoO42−/MgAl-LDH was produced by adding 0.01 mol NaMoO4·2H2O and 12.5 mL of deionized water as liquid C in the hydrothermal process.
Preparation of MoS2/MgAl-LDH: The product MoO42−/MgAl-LDH was weighed as 0.5 g. The molar ratio of S to Mo was 4:1, hence 3.0448 g of thiourea (equivalent to 0.01 mol NaMoO4·2H2O) was weighed. We mixed the two, added 60 mL of deionized water, and stirred continuously until dissolved. We transferred the solution to a 100 mL hydrothermal kettle and heated it at 200 °C for 24 h. The hydrothermal product was washed, pumped, and filtered before vacuum freeze-drying for 10 h to provide the MoS2/MgAl-LDH. According to the amount of different MoS2 loaded, the sample was labeled as MoS2/MgAl-LDH-n.

3.2. Characterizations

The crystal structure was analyzed using X-ray diffraction (XRD) (D/MAX2200, Rigaku Co., Tokyo, Japan). The sample morphology and elemental mapping were examined using a scanning electron microscope (SEM) (JSM-7900F, JEOL, Tokyo, Japan). The chemical composition and state of the sample were identified using an ESCALABX XPS spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). UV-visible diffuse reflectance spectroscopy (Cary 5000, Agilent, Santa Clara, CA, USA) was used to record the light absorption spectra. The photoelectrochemical measurements, including photocurrent response (i-t) and electrochemical impedance (EIS), were taken using an electrochemical workstation (CHI-660E, Chenhua Instrument, Shanghai, China).

3.3. Photocatalystic Degration of RhB

The photocatalytic performance of MoS₂/MgAl-LDH was evaluated through the degradation of RhB using a 300 W full-spectrum xenon lamp (HF-GHX-XE-300, Hefan, Shanghai, China). In the subsequent tests, a 100 mL glass was filled with 50 mL of RhB aqueous solution (30 mg/L) and 20 mg of catalyst powder and was kept without light for 30 min to bring about the balance between adsorption and desorption. The light source was turned on, beginning the photocatalytic degradation reaction, and it was sampled at regular intervals. After centrifuging the samples, the supernatant was collected for future examinations. For the cyclic degradation studies, the samples obtained after each separation were collected and cleaned with ethanol and deionized water and then dried. The dried photocatalysts were then reintroduced into fresh RhB solutions to repeat the degradation studies using the aforementioned protocols. The absorbance of the samples was measured with a UV-Vis spectrophotometer (Imax = 536 nm), and the degradation rate was then computed. The catalytic degradation rate was quantified using a first-level kinetic model. The fitting formula is as follows: −In (C/Co) = kt.

4. Conclusions

In summary, MoS2 was successfully loaded onto MgAl-LDH using two hydrothermal procedures, resulting in MoS2/MgAl-LDH composite materials. MgAl-LDH has a broadsheet structure, and MoS2 becomes more diffuse. The photocatalytic efficiency of Rhodamine B was enhanced by altering the MoS2 load, and it was 69.2% higher than MgAl-LDH alone. The built-in electric field between MgAl-LDH and MoS2 was measured using XPS and electrochemical test grades, which significantly increased carrier separation and transfer efficiency while also improving MgAl-LDH’s photocatalytic performance. In this study, MgCl2·6H2O was used as a magnesium source to greatly improve the photocatalytic performance of MoS2/MgAl-LDH composite, laying the groundwork for future green cycle applications of by-product magnesium resources in salt lakes.

Author Contributions

Conceptualization, G.Y. and H.N.; methodology, J.D. and G.L.; experimental, J.D. and Y.W.; validation, Y.W.; investigation, C.Z.; resources, H.N.; data curation, J.D.; writing—original draft preparation, J.D.; writing—review and editing, G.Y.; supervision, G.Y. All authors have read and agreed to the published version of the manuscript.

Funding

This research was supported by the Open Project of Salt Lake Chemical Engineering Research Complex, Qinghai University (2024-DXSSKF-08).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data that support the findings of this study are available within the article.

Acknowledgments

The author extend their appreciation to the Open Project of Salt Lake Chemical Engineering Research Complex, Qinghai University (2024-DXSSKF-08), Qinghai University for supporting this research.

Conflicts of Interest

The authors declare no conflicts of interest.

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Inorganics 13 00088 g001
Figure 1. XRD patterns of MgAl-LDH and MoS2/MgAl-LDH.
Figure 1. XRD patterns of MgAl-LDH and MoS2/MgAl-LDH.
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Figure 2. SEM of MgAl-LDH (a) and MoS2/MgAl-LDH (b), and EDS of MoS2/MgAl-LDH (c–f).
Figure 2. SEM of MgAl-LDH (a) and MoS2/MgAl-LDH (b), and EDS of MoS2/MgAl-LDH (c–f).
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Figure 3. (a) XPS survey, the XPS spectra of (b) Mg, (c) Mo 3d, (d) S 2p of MoS2/MgAl-LDH.
Figure 3. (a) XPS survey, the XPS spectra of (b) Mg, (c) Mo 3d, (d) S 2p of MoS2/MgAl-LDH.
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Inorganics 13 00088 g004
Figure 4. The standard curve for RhB degradation (a), the photocatalytic activity of samples for RhB degradation (b), degradation kinetic plot of ln (C0/Ct) vs. time (c), and cyclic experiments of MoS2/MgAl-LDH-2 for the degradation of RhB (d).
Figure 4. The standard curve for RhB degradation (a), the photocatalytic activity of samples for RhB degradation (b), degradation kinetic plot of ln (C0/Ct) vs. time (c), and cyclic experiments of MoS2/MgAl-LDH-2 for the degradation of RhB (d).
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Figure 5. UV-vis diffuse reflectance spectra of samples (a) and Tauc plot of MoS2/MgAl-LDH (b), MoS2 (c), and MgAl-LDH (d).
Figure 5. UV-vis diffuse reflectance spectra of samples (a) and Tauc plot of MoS2/MgAl-LDH (b), MoS2 (c), and MgAl-LDH (d).
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Inorganics 13 00088 g006
Figure 6. Electrochemical AC impedance of samples (a), transient photocurrent response of MgAl-LDH and MoS2/MgAl-LDH-2 (b), Mott-Schottky curves structure plots of MgAl-LDH (c), MoS2 (d), and the XPS-VB of MoS2 (e) MgAl-LDH (f).
Figure 6. Electrochemical AC impedance of samples (a), transient photocurrent response of MgAl-LDH and MoS2/MgAl-LDH-2 (b), Mott-Schottky curves structure plots of MgAl-LDH (c), MoS2 (d), and the XPS-VB of MoS2 (e) MgAl-LDH (f).
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Figure 7. Photocatalytic degradation production mechanism of MoS2/MgAl-LDH. Before and (a) after contact in the dark state (b) contact under light irradiation (c).
Figure 7. Photocatalytic degradation production mechanism of MoS2/MgAl-LDH. Before and (a) after contact in the dark state (b) contact under light irradiation (c).
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Table 1. Pseudo first-order photocatalytic kinetic correlation coefficients of MoS2/MgAl-LDH composite materials under different loads and amounts of MoS2.
Table 1. Pseudo first-order photocatalytic kinetic correlation coefficients of MoS2/MgAl-LDH composite materials under different loads and amounts of MoS2.
SamplesKobs/min−1R2
MgAl-LDH0.00080.9669
MoS2/MgAl-LDH-10.00230.9572
MoS2/MgAl-LDH-20.00770.9936
MoS2/MgAl-LDH-30.00730.9922
Table 2. The band potential of MgAl-LDH and MoS2.
Table 2. The band potential of MgAl-LDH and MoS2.
SamplesMgAl-LDHMoS2
CB−0.49 eV−0.23 eV
VB4.52 eV1.19 eV
Band gap5.01 eV1.42 eV
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Dai, J.; Li, G.; Wang, Y.; Zhang, C.; Nan, H.; Yang, G. MoS2/MgAl-LDH Composites for the Photodegradation of Rhodamine B Dye. Inorganics 2025, 13, 88. https://doi.org/10.3390/inorganics13030088

AMA Style

Dai J, Li G, Wang Y, Zhang C, Nan H, Yang G. MoS2/MgAl-LDH Composites for the Photodegradation of Rhodamine B Dye. Inorganics. 2025; 13(3):88. https://doi.org/10.3390/inorganics13030088

Chicago/Turabian Style

Dai, Jingjing, Guofei Li, Yuanyuan Wang, Cancan Zhang, Hui Nan, and Guijun Yang. 2025. "MoS2/MgAl-LDH Composites for the Photodegradation of Rhodamine B Dye" Inorganics 13, no. 3: 88. https://doi.org/10.3390/inorganics13030088

APA Style

Dai, J., Li, G., Wang, Y., Zhang, C., Nan, H., & Yang, G. (2025). MoS2/MgAl-LDH Composites for the Photodegradation of Rhodamine B Dye. Inorganics, 13(3), 88. https://doi.org/10.3390/inorganics13030088

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