Development of Rh-Doped Ga2O3 Photocatalysts for Reduction of CO2 by H2O as an Electron Donor at a More than 300 nm Wavelength
Development of Rh-Doped Ga2O3 Photocatalysts for Reduction of CO2 by H2O as an Electron Donor at a More than 300 nm Wavelength
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DOI：
10.1021/acs.jpcc.8b04956
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发表时间：
2018-09-20
影响因子：
3.7
通讯作者：
Tanaka, Tsunehiro
中科院分区：
文献类型：
--
作者：
Kikkawa, Soichi;Teramura, Kentaro;Tanaka, Tsunehiro
通过简单的共沉淀法制备的铑掺杂氧化镓（Ga2O3:Rh）在>300 nm波长的光照射下表现出H2O光催化转化CO2的活性。尽管Ga2O3是一种宽带隙光催化剂，但由于Rh掺杂，仅在300 nm的光照射下才具有活性。负载Ag-Cr的Ga2O3:Rh (0.7 mol %)显示出作为CO还原产物产生CO (3.9 mu mol h(-1))的活性。化学计量的O-2的形成表明H2O充当CO2光催化转化的电子供体。使用 X 射线吸收光谱 (XAS) 等多种技术进行表征表明，掺杂 Ga2O3 后，三价 Rh 物质不是取代四面体 Ga 位点，而是取代 β-Ga2O3 的八面体 Ga 位点。从DFT计算结果来看，Rh3+产生的新能级位于Ga2O3带隙内。结论是，导带上的Rh d t(2g)轨道的新吸收有助于在>300 nm波长的光照射下H2O光催化转化CO2的活性。
Rhodium-doped gallium oxide (Ga2O3:Rh) that was prepared by a simple coprecipitation method exhibited activity for the photocatalytic conversion of CO2 by H2O under photoirradiation with light of >300 nm wavelength. Although Ga2O3 is a wide-band-gap photocatalyst that is active only under photoirradiation with 300 nm as a result of Rh doping. Ag-Cr-loaded Ga2O3:Rh (0.7 mol %) showed activity for the production of CO (3.9 mu mol h(-1)) as a reduction product of CO,. The formation of a stoichiometric amount of O-2 indicated that H2O acts as an electron donor for the photocatalytic conversion of CO2. Characterization using several techniques such as X-ray absorption spectroscopy (XAS) revealed that after doping in Ga2O3 the trivalent Rh species substituted not for the tetrahedral Ga site but for the octahedral Ga site of beta-Ga2O3. From the result of DFT calculations, the new energy level owing to Rh3+ was within the Ga2O3 band gap. It was concluded that the new absorption due to the Rh d t(2g) orbital to the conduction band contributed to the activity of photocatalytic conversion of CO2 by H2O under photoirradiation with light of >300 nm wavelength.