MoO 3 /S@g-C 3 N 4 Nanocomposite Structures: Synthesis, Characterization, and Hydrogen Catalytic Performance.

Hydrogen production as a source of clean energy is high in demand nowadays to avoid environmental issues originating from the use of conventional energy sources i.e., fossil fuels. In this work and for the first time, MoO 3 /S@g-C 3 N 4 nanocomposite is functionalized for hydrogen production. Sulfur@graphitic carbon nitride (S@g-C 3 N 4 )-based catalysis is prepared via thermal condensation of thiourea. The MoO 3 , S@g-C 3 N 4 , and MoO 3 /S@g-C 3 N 4 nanocomposites were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FESEM), STEM, and spectrophotometer. The lattice constant (a = 3.96, b = 13.92 Å) and the volume (203.4 Å 3 ) of MoO 3 /10%S@g-C 3 N 4 were found to be the highest compared with MoO 3 , MoO 3 /20-%S@g-C 3 N 4 , and MoO 3 /30%S@g-C 3 N 4 , and that led to highest band gap energy of 4.14 eV. The nanocomposite sample MoO 3 /10%S@g-C 3 N 4 showed a higher surface area (22 m 2 /g) and large pore volume (0.11 cm 3 /g). The average nanocrystal size and microstrain for MoO 3 /10%S@g-C 3 N 4 were found to be 23 nm and -0.042, respectively. The highest hydrogen production from NaBH 4 hydrolysis ~22,340 mL/g·min was obtained from MoO 3 /10%S@g-C 3 N 4 nanocomposites, while 18,421 mL/g·min was obtained from pure MoO 3 . Hydrogen production was increased when increasing the masses of MoO 3 /10%S@g-C 3 N 4 .