**4. Conclusions**

In summary, MoS2 nanoflowers were composited with the MWCNT network via a facile self-assembling strategy to boost the bolometric performance. The <sup>α</sup>-*T* curve demonstrated that the MoS2 nanoflowers provide significant phonon scattering and affect the intertube interfaces, decreasing α by 51%. As the temperature increased from 296 K to 320 K, the relative TCR increased from 0.04%*/*K to 0.25%*/*K. The detection experiment under low laser power proved that the CNT–MoS2 composite network had strong sensitivity. It showed 5–18-fold enhancements in resistive responsivity compared with the pure CNT network to the 405–1550 nm laser irradiation at room temperature (RT). Under 2 mW/mm<sup>2</sup> power density for the 1550 nm laser, the responsivity reached 3.61%. The response time range of the 350-μm-long sample was about 11.76–12.25 ms, which was consistent with the joule heating result. This confirmed that the photoresponse of the CNT–MoS2 composite network was bolometric. The simple device structure and the removal of the requirement for high-quality CNTs represent steps forward towards the wide application of CNT-based IR detectors.

**Supplementary Materials:** The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/nano12030495/s1 Figure S1. Measure the diameter of (a) 405 nm, (b) 860 nm, (c) 1064 nm, and (d) 1550 nm laser through knife edge technique [66]; Figure S2. Lowand High- magnification of SEM images of the sample 1 with low MoS2 decoration; Figure S3. Low resolution of SEM images of the CNT-MoS2 composite network; Figure S4. The measured *α* and resistivity of the composite network at different temperatures (296 K-320 K). The measurement uncertainty of *α* based on the TET technique is ±10%, which is omitted in the figure for better comparison; Figure S5. the *R*-*P* curve comparison of the CNT-MoS2 composite network under low laser power irradiation with different wavelength: (a) 405 nm, (b) 860 nm, (c) 1064 nm, (d) 1550 nm and (e) the comparison of the dR/R-PD (power density) curve; Figure S6. the *R*-*P* curve of the pure CNT network with different wavelength: (a) 405 nm, (b) 860 nm, (c) 1064 nm, and (d) 1550 nm; Figure S7. the dR/R-PD (power density) curve of the pure CNT network under laser irradiation with different wavelength: (a) 405 nm, (b) 860 nm, (c) 1064 nm, and (d) 1550 nm; Figure S8. the dR/R-PD curve of the CNT-MoS2 composite network under laser irradiation with different wavelength: (a) 405 nm, (b) 860 nm, (c) 1064 nm, and (d) 1550 nm; Figure S9. The normalized voltage-time profiles of the pure CNT network under the laser irradiation of different wavelength: (a) 405 nm, (b) 860 nm, (c) 1064 nm, and (d) 1550 nm; Figure S10. The normalized voltage-time profiles of the CNT-MoS2 composite network under the laser irradiation of different wavelength: (a) 405 nm, (b) 860 nm, (c) 1064 nm, and (d)1550 nm; Figure S11. the voltage-time profiles of the composite network under the modulated laser heating and the joule heating. (With offset for comparison)

**Author Contributions:** Conceptualization, Y.X.; methodology, Q.W., Y.X.; formal analysis, Q.W., L.X.; investigation, Q.W., Y.W., X.D.; data curation, Q.W., Y.W., X.D., K.X.; writing—original draft preparation, Q.W.; writing—review and editing, Y.X., Y.L., K.X. All authors have read and agreed to the published version of the manuscript.

**Funding:** National Natural Science Foundation of China (No. 51906161), Natural Science Foundation of Guangdong Province (No. 2020A1515011186), Educational Commission of Guangdong Province of China (No 2020ZDZX2011), the Start-Up Fund of Shenzhen University (QNJS0069), and the Scientific Research Foundation for Talented Scholars in Shenzhen (RC00052).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable. **Conflicts of Interest:** The authors declare no conflict of interest.
