Biochar-engineered Bio-MXene for enhanced visible-light photocatalytic hydrogen evolution

This study details the synthesis and characterization of Bio-MXene materials derived from sawdust-based biochar, emphasizing their improved efficacy in photocatalytic hydrogen evolution under visible light. The incorporation of biochar enhances charge separation and promotes the absorption of visible light. This results in a reduction of the bandgap to approximately 1.47 eV and an increase in the spacing between the layers. Upon exposure to visible light (λ > 420 nm), the Bio-MXene demonstrates an apparent quantum yield (AQY) of around 14.5% and a hydrogen evolution rate of about 24 mmol g−1 h−1. The analysis through electrochemical impedance spectroscopy reveals a reduction in charge transfer resistance to 260 Ω, while photoluminescence assessment suggests a diminished likelihood of electron-hole recombination. The photocatalyst demonstrates sustained activity, maintaining over 90% effectiveness after five cycles, which suggests its stability and potential for reuse. This investigation presents an economical and eco-conscious method for transforming biomass waste into effective photocatalysts that improve hydrogen production powered by solar energy.