Abstract In this study, the Cr2O3/C@TiO2 composite was synthesized via the calcination of yolk–shell MIL-101@TiO2. The composite presented core–shell structure, where Cr-doped TiO2 and Cr2O3/C were the shell and core, respectively. The introduction of Cr3+ and Cr2O3/C, which were derived from the calcination of MIL-101, in the composite enhanced its visible light absorbing ability and lowered the recombination rate of the photogenerated electrons and holes. The large surface area of the Cr2O3/C@TiO2 composite provided numerous active sites for the photoreduction reaction. Consequently, the photocatalytic performance of the composite for the production of H2 was better than that of pure TiO2. Under the irradiation of a 300 W Xe arc lamp, the H2 production rate of the Cr2O3/C@TiO2 composite that was calcined at 500 dC was 446 μmol h−1 g−1, which was approximately four times higher than that of pristine TiO2 nanoparticles. Moreover, the composite exhibited the high H2 production rate of 25.5 μmol h−1 g−1 under visible light irradiation (λ > 420 nm). The high photocatalytic performance of Cr2O3/C@TiO2 could be attributed to its wide visible light photoresponse range and efficient separation of photogenerated electrons and holes. This paper offers some insights into the design of a novel efficient photocatalyst for water-splitting applications.

中文翻译：

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用于光催化制氢的核壳纳米结构Cr2O3/C@TiO2的合成

摘要 在本研究中，通过煅烧蛋黄-壳 MIL-101@TiO2 合成了 Cr2O3/C@TiO2 复合材料。复合材料呈现核壳结构，其中掺铬的 TiO2 和 Cr2O3/C 分别是壳和核。MIL-101煅烧产生的Cr3+和Cr2O3/C的引入增强了复合材料的可见光吸收能力，降低了光生电子和空穴的复合率。Cr2O3/C@TiO2 复合材料的大表面积为光还原反应提供了许多活性位点。因此，复合材料对制氢的光催化性能优于纯 TiO2。在 300 W Xe 弧光灯照射下，500 dC 煅烧的 Cr2O3/C@TiO2 复合材料的产氢率为 446 μmol h−1 g−1，大约是原始 TiO2 纳米粒子的四倍。此外，该复合材料在可见光照射下（λ > 420 nm）表现出 25.5 μmol h-1 g-1 的高产氢率。Cr2O3/C@TiO2 的高光催化性能可归因于其宽的可见光光响应范围和光生电子和空穴的有效分离。本文为设计用于水分解应用的新型高效光催化剂提供了一些见解。Cr2O3/C@TiO2 的高光催化性能可归因于其宽的可见光光响应范围和光生电子和空穴的有效分离。本文为设计用于水分解应用的新型高效光催化剂提供了一些见解。Cr2O3/C@TiO2 的高光催化性能可归因于其宽的可见光光响应范围和光生电子和空穴的有效分离。本文为设计用于水分解应用的新型高效光催化剂提供了一些见解。