Biopolymer supported silicon carbide for enhanced photocatalytic hydrogen evolution reaction

Abstract

In photocatalytic hydrogen evolution reactions, SiC catalyst was templated with biopolymers (cellulose, chitin, chitosan, sodium alginate) in a reaction medium containing eosin Y dye and triethanolamine. Biopolymers act as biotemplate and mediator, provide easy dispersion, hydrophilicity, morphological transformation and adhesion to semiconductor with the help of functional groups. The photo-deposition of MoSx and Pt in aqueous solution is performed on biopolymer-SiC nanocomposite to obtain biopolymer-SiC/MoSx and biopolymer-SiC/Pt by reducing (NH4)2MoS4 and H2PtCl6·6H2O, respectively. Sodium alginate-SiC/MoSx showed highest photocatalytic activity which is approximately 158-, 34- and 13 times higher than bare SiC, bare sodium alginate and sodium alginate-SiC catalyst, respectively. Moreover, the solar-to-hydrogen efficiencies are achieved about 19.83% under solar light irradiation for the sodium alginate-SiC/MoSx catalyst. In addition, photo-deposited MoSx and Pt on biopolymer-SiC nanocomposite resulted in enhanced photocatalytic activity and stability because of increased active sites and enhanced electron transfer ability due to the co-catalyst effect.