MoO3/S@g-C3N4 Nanocomposite Structures: Synthesis, Characterization, and Hydrogen Catalytic Performance.

Abstract

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, MoO3/S@g-C3N4 nanocomposite is functionalized for hydrogen production. Sulfur@graphitic carbon nitride (S@g-C3N4)-based catalysis is prepared via thermal condensation of thiourea. The MoO3, S@g-C3N4, and MoO3/S@g-C3N4 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 Å3) of MoO3/10%S@g-C3N4 were found to be the highest compared with MoO3, MoO3/20-%S@g-C3N4, and MoO3/30%S@g-C3N4, and that led to highest band gap energy of 4.14 eV. The nanocomposite sample MoO3/10%S@g-C3N4 showed a higher surface area (22 m2/g) and large pore volume (0.11 cm3/g). The average nanocrystal size and microstrain for MoO3/10%S@g-C3N4 were found to be 23 nm and -0.042, respectively. The highest hydrogen production from NaBH4 hydrolysis ~22,340 mL/g·min was obtained from MoO3/10%S@g-C3N4 nanocomposites, while 18,421 mL/g·min was obtained from pure MoO3. Hydrogen production was increased when increasing the masses of MoO3/10%S@g-C3N4.