An ultrahigh hydrogen production rate of photocatalyst Fe2S2(CO)6/MoS2/CdS integrated mimic hydrogenase and capacitor for H2 evolution with longer lifetime of photoexcited electrons

Abstract

The hydrogenase mimics provide an innovative strategy for photocatalytic hydrogen production; however, the efficiency mismatch between electron production and utilization results in low hydrogen production rate. Herein, we report the integration of non-noble metal cocatalyst MoS2 decorated with hydrogenase model complex Fe2S2(CO)6 and CdS QDs to assemble Fe2S2(CO)6/MoS2/CdS QDs, which exhibited an excellent hydrogen production rate of 10,836 μmol/g/h. This rate is 127.4, 9.1, and 1.6 times higher than that of CdS QDs, Fe2S2(CO)6/CdS QDs, and MoS2/CdS QDs, respectively. In comparison to CdS or MoS2/CdS, transient photovoltage (TPV) measurements revealed that the photovoltage response of Fe2S2(CO)6/MoS2/CdS increased numerically by 3.3 times; meanwhile, Fe2S2(CO)6/MoS2/CdS significantly extended the lifetime of photo-generated electrons. The excellent performance was attributed to the distinct capacitance effect and functional active site of Fe2S2(CO)6/MoS2/CdS, which boosted electron storage and redistribution at the interface to alleviate recombination losses and facilitate hydrogen production.