MWCNT/Ga_0.3(In_0.2Cd_0.8)_0.7S Photocatalysts with Enhanced Hydrogen Evolution Activity for Water-Splitting

Abstract This study investigates the application of Ga0.3(In0.2Cd0.8)0.7S photocatalysts, modified with multi-walled carbon nanotubes (MWCNTs) at varying concentrations, for hydrogen evolution in water-splitting reactions. The results demonstrate that Ga0.3(In0.2Cd0.8)0.7S photocatalysts with 0.242 wt% MWCNT achieve the highest photocatalytic activity, yielding a photocurrent density of 3.66 mA/cm² under UV-vis light and 1.49 mA/cm² under visible light. In hydrogen evolution tests, the catalyst exhibited hydrogen production rates of 1.84 and 0.73 mmol/hr·mg under UV-vis and visible light, respectively, outperforming pure Ga0.3(In0.2Cd0.8)0.7S photocatalysts by factors of 1.34 and 2.4. The enhanced performance is attributed to the unique properties of MWCNTs, which serve as excellent conductive carriers with high surface area and superior electron mobility. The integration of an appropriate concentration of MWCNTs into Ga0.3(In0.2Cd0.8)0.7S enhances the catalyst’s electrical conductivity and reduces interfacial resistance, enabling rapid electron transport pathways, reducing electron-hole recombination rates, and consequently improving both photocurrent and hydrogen evolution efficiency.