*2.2. Equipment*

When suspending the bi-nanoparticles in the deionized (DIW) water, a sonicator (Hielscher, Germany) was employed to homogenize the mixture. A programmable water bath (LAUDA ECO RE1225, Berlin, Germany) was deployed to keep the mixture at a low temperature during sonication and used to keep the nanofluids at the specific temperatures while measuring the thermophysical properties. Other pieces of equipment, such as a digital weighing balance (Radwag AS 220.R2 (Radom, Poland) with an accuracy of ±0.01 g), pH meter (Jenway 3510, Staffordshire, UK; –2 to 19.999 range with ±0.003 accuracy), vibro-viscometer (SV-10; A&D, Tokyo, Japan; with ±3% accuracy), UV–visible spectrophotometer (Jenway, Staffordshire, UK), transmission electron microscope (JEOL JEM-2100F, Tokyo, Japan)—dry sample type, and electrical conductivity meter (EUTECH Instrument (Singapore) with ±1% accuracy), were used for various purposes in this work.
