Cu atoms on UiO-66-NH2/ZnIn2S4 nanosheets enhance photocatalytic performance for recovering hydrogen energy from organic wastewater treatment

The extensive use of sacrificial agents and the low carrier separation and utilization efficiency remain important factors limiting the development of photocatalytic hydrogen production. We report a three-layered, dual-functional photocatalysts of Cu atomics@UiO-66-NH2(U6N)/ZnIn2S4 nanosheets (ZIS), for the simultaneous production of photocatalytic hydrogen and degradation of organic pollutants. When common and highly toxic organic pollutants (phenolic compounds and antibiotics) were substituted for the sacrificial agents, Cu@U6N/ZIS exhibited superior sustained hydrogen production, approximately 28 times greater than that of pure ZIS. The experimental results suggested that the window size of U6N (< organic pollutants molecular size) separates the reaction sites of organic pollutants oxidation and reduction of hydrogen ions (H+), thereby achieving spatial separation of redox sites. Besides, the structure of Cu@U6N/ZIS, which was anchored Cu within U6N and encapsulated by ZIS nanosheets, forming Z-type heterojunctions, achieved the control of the directional transfer of photogenerated electrons. And the coupled system can effectively enhance water quality by reducing the biological toxicity of the wastewater. This study suggests new avenues for environmental restoration and non-fossil fuel production.