Facile fabrication of mesoporous biochar/ZnFe2O4 composite with enhanced visible-light photocatalytic hydrogen evolution

A promising biochar/ZnFe2O4 (BZF) composite has been synthesized to improve the efficiency of visible-light-driven H2 evolution via a simple microwave hydrothermal method. The materials were investigated through diverse characterization means including XRD, FTIR, SEM, BET, XPS, VSM, UV–vis/DRS, PL, EIS. Different ratios of BZF composites expressed enhanced photocatalytic H2 evolution performance over pure ZnFe2O4. Especially, biochar/ZnFe2O4 catalysts with 5:1 mass ratio (BZF-5) attained the optimal H2 evolution rate, which is around 6 times higher than that of pure ZnFe2O4. Biochar acts as an electron mediator can effectively promote the separation of electron-hole pairs to enhance the rate of photocatalytic hydrogen evolution. Moreover, Eosin Y, photocatalyst and TEOA have synergistic effects accounted for enhanced photocatalytic performance in reaction system. Three cyclic runs for the photocatalytic H2 evolution on BZF-5 sample illustrated its good stability and sustainable reusability.