扩展的数据图。4: Self-heated photocatalytic OWS system.

a, Self-heated photocatalytic OWS system.b, Schematic parameters of the self-heated photocatalytic OWS system.c,d, Thermodynamic parameters of the reaction system (c) without and (d) with a heat-insulating layer. The heat-insulating layer (thickness of approximately 0.5 cm) consisted of ordinary A4 printing paper. The wall thickness of the Prexy chamber was approximately 0.3 cm.e, Synergetic effect mechanism of promoting forward hydrogen–oxygen evolution and inhibiting the reverse hydrogen–oxygen recombination in the photocatalytic OWS. The UV-vis light was responsible for the production of photogenerated electrons and holes via the photoexcitation of InGaN/GaN semiconductor, which can further cause the redox of water. Although the infrared light was non-effective for the photoexcitation of InGaN/GaN, it could produce a substantial thermal effect to promote hydrogen/oxygen production and simultaneously inhibit the hydrogen–oxygen recombination. In this mechanism, the infrared light indirectly, but substantially improved the utilization efficiency of UV-vis light by enhancing the surface catalytic hydrogen/oxygen production, which finally contributed to the maximizing of STH. A thermal transfer balance existed in our system during photocatalytic reaction, which was influenced by the thermal conductivity coefficients of materials used in the reaction system. The role of the heat-insulating layer was to produce a larger temperature difference between ambient and internal environment of reaction system. The thermal conductivity coefficients of Prexy glass, heat-insulating layer and water were 1,143, 50 and 600 mW m⁻¹K⁻¹, respectively. In the absence of the heat-insulating layer, the temperature of water in the chamber was maintained at roughly 50 °C. However, with the addition of low thermal-conductivity heat-insulating layer, the temperature of reaction system could be increased to approximately 70 °C under the same IR input (428 mW). The species and content of impurities in tap water can be found on the website of Ann Arbor Water Treatment Services Unit (https://www.a2gov.org/departments/water-treatment/Documents/water_quality_report_2020.pdf).