Samarium vanadate affixed sulfur self doped g-C3N4 heterojunction; photocatalytic, photoelectrocatalytic hydrogen evolution and dye degradation

Abstract

The Thermal polycondensation method was used to make sulfur self-doped graphitic-carbon nitride (SCN) sheets that were anchored with samarium vanadate (SmV). The decorating of SmV nanoparticles on sheets of SCN is confirmed by X-ray diffraction, spectroscopic, and microscopic characterizations. When compared to the bandgap of pure SmV (2.16 eV) and SCN (2.44 eV), SmV decorating decreased the bandgap of SCN to 1.89 eV. The lowered bandgap in SmV/SCN and the formation of type II heterostructure resulted in improved performance in photoelectrochemical and photochemical hydrogen evolution and photocatalytic degradation experiments. The amount of hydrogen evolution was high in SmV/SCN which was found to be 22,618 μmol g −1 of H 2 in 4 h under photochemical conditions. The obtained onset potential at 10 mA cm 2 is −190 mV under photoelectrochemical studies. The SmV/SCN was able to absorb visible light and degraded Methyl orange (MO). The reaction conditions were thoroughly optimized, found pH 8, 10 mg L −1 initial concentration of dye and 25 mg of SmV/SCN as an optimum condition under visible light. The degradation efficiency was up to 90% in just 80 min. Scavenger investigations were used to identify the active species (OH . and . O 2 − ) and indicate which were then confirmed by electron spin resonance spectroscopic (ESR) experiments. The mechanism of photocatalysis has been well explored. The obtained results show that the SmV/SCN nanocomposite is capable of serving a choice of material for energy and environmental applications. • SmVO 4 decorated on S doped g-C 3 N 4 sheets. • Decrease in the bandgap of g-C 3 N 4 upon decoration of SmVO 4 (1.89 eV). • Enhanced H 2 evolution both in photoelectrochemical and photochemical. • Visible light driven degradation of Methyl orange (90%). • Detailed mechanism of photocatalysis based on heterostructure of Type-II.