Eco-friendly rice husk derived biochar as a highly efficient noble Metal-Free cocatalyst for high production of H2 using solar light irradiation

Eco-friendly, low-cost, and highly efficient noble metal-free rice husk (RH) biomass-derived biochar (BC) was developed as an efficient cocatalyst to improve the performance of zinc indium sulfide (ZnIn2S4) for the photocatalytic H2 production. The ZnIn2S4 and BC were synthesized using simple hydrothermal and pyrolysis methods, respectively. The ZnIn2S4 was converted into few-layered ZnIn2S4 nanosheets (ZIS) after the incorporation on BC using ultra-sonication process. The optimized nanocomposite exhibited superior H2 production (4,466 μmol h−1 g−1) compared to pristine ZIS under the simulated light irradiation. The stability of catalyst was confirmed by long-term (30 h) photo-experiment and recycling studies. Enhanced activity was the result of efficient interfacial contacts between the materials in addition to high surface area, high conductivity with carbon content, porous structure of BC, and ultrathin-layered structure of ZIS nanosheets. The effective photo-induced charge carrier separation, improved long-life shuttling, and subsequent acceleration has led to enhanced visible light absorption for enhanced H2 production.