Abstract A series of heterojunction catalysts (CuCN-X) were successfully fabricated by loading the different amounts of Keggin type Cu mono-substituted heteropoly acid (HPW11Cu) on the surface of hollow nanospheres g-C3N4 (HSCN). The HSCNs were prepared by using SiO2 as a hard template. The chemical structure, porosity, morphology and electronic property of the prepared catalysts were investigated using XRD, SEM, N2-absorption isotherm and XPS. The results indicated that the modified HSCN show prominent absorption in the visible light range and decrease the band gap. The greatly enhanced photocatalytic activity of obtained CuCN-X have been shown by the degradation of Rhodamine B (RhB), reduction of CO2 and production of photocatalytic hydrogen under visible light irradiation. More significantly, CuCN-15 has shown significantly improved photocatalytic performance at 4.5, 3.5 and 3.3 times higher that of than HSCN for the degradation of RhB, reduction of CO2 and production of photocatalytic hydrogen, respectively. Furthermore, the mechanism for the enhanced photocatalytic activity of CuCN-X is proposed to be due to the formation of heterojunction. The electrons can be rapidly transferred from HSCN to HPW11Cu, in which facilitate charge separation and charge transfer. Graphical Abstract

中文翻译：

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Keggin型Cu单取代杂多酸负载空心纳米球g-C3N4的制备具有增强的可见光捕获和电子转移性能，用于高效光催化

摘要 通过在空心纳米球g-C3N4（HSCN）表面负载不同量的Keggin型Cu单取代杂多酸（HPW11Cu），成功制备了一系列异质结催化剂（CuCN-X）。HSCNs 是通过使用 SiO2 作为硬模板制备的。使用XRD、SEM、N2吸收等温线和XPS研究了所制备催化剂的化学结构、孔隙率、形貌和电子性质。结果表明，改性HSCN在可见光范围内表现出显着的吸收并降低了带隙。通过在可见光照射下降解罗丹明 B (RhB)、还原 CO2 和产生光催化氢气，所获得的 CuCN-X 的光催化活性大大增强。更重要的是，CuCN-15在降解RhB、还原CO2和产生光催化氢气方面的光催化性能分别比HSCN高4.5、3.5和3.3倍。此外，CuCN-X 光催化活性增强的机制被认为是由于异质结的形成。电子可以从 HSCN 快速转移到 HPW11Cu，促进电荷分离和电荷转移。图形概要 电子可以从 HSCN 快速转移到 HPW11Cu，促进电荷分离和电荷转移。图形概要 电子可以从 HSCN 快速转移到 HPW11Cu，促进电荷分离和电荷转移。图形概要