Enhanced H2 evolution of TiO2 with efficient multiple electrons transfer modified by tiny CuOx–NiO bimetallic oxides
Enhanced H2 evolution of TiO2 with efficient multiple electrons transfer modified by tiny CuOx–NiO bimetallic oxides
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DOI：
10.1016/j.ijhydene.2018.03.083
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发表时间：
2018-04
影响因子：
7.2
通讯作者：
Meng Zhang;Runze Sun;Gaoyuan Long;Chidong Zhou;Yanfang Zhou;Mengxia Chen;Xiuying Huang;Gaorui Han-Gaor
中科院分区：
文献类型：
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作者：
Meng Zhang;Runze Sun;Gaoyuan Long;Chidong Zhou;Yanfang Zhou;Mengxia Chen;Xiuying Huang;Gaorui Han-Gaor
采用沉淀-光还原法制备了CuOx-NiO复合氧化物改性TiO 2催化剂，并用于光催化制氢。0.9%Cu0.1%Ni/TiO 2催化剂在350-780 nm紫外可见光照射下的析氢速率最高（55.4 μmol/g/min），高于CuOx/TiO 2和NiO/TiO 2催化剂的总和。与沉积在TiO 2上相比，沉积在NiO/TiO 2上的Cu物种表现出更多的还原价态，包括Cu 0.通过光电子化学分析证实，多价铜物种导致增强的光电流和降低的转移电阻。CuOx-NiO改性有利于TiO 2表面的光激发电子转移，抑制了电子复合。光激发电子寿命从1.16 ns（TiO 2）提高到5.15 ns（CuOx-NiO/TiO 2）。通过分析，提出了多价双金属氧化物共改性TiO 2的多电子转移机理。本工作展示了一种具有高效光催化产氢功能的多价金属氧化物改性TiO 2体系，为多价金属氧化物助催化剂的设计和产氢机理提供了一些有意义的理解。
CuOx–NiO bimetallic oxides modified TiO2catalysts were prepared via a precipitation-photoreduction approach for photocatalytic H2production. 0.9%Cu0.1%Ni/TiO2exhibited the highest H2evolution rate (about 55.4 μmol/g/min) under UV–visible light irradiation (350–780 nm), which is higher than the sum of CuOx/TiO2and NiO/TiO2catalyst. Cu species exhibited more reducing valence state including Cu0when deposited on NiO/TiO2compared with deposited on TiO2. The polyvalent Cu species lead to enhanced photocurrent and reduced transfer resistance confirmed by photoelectron chemical analysis. CuOx–NiO modification of the TiO2surface is beneficial for the photoexcited electron transfer, which suppresses electrons recombination. The lifetime of photoexcited electrons was enhanced greatly from 1.16 (TiO2) to 5.15 ns (CuOx–NiO/TiO2). A multiple electrons transfer mechanism for polyvalent bimetallic oxides co-modified TiO2was proposed based on careful analysis. This work demonstrated a polyvalent bimetallic oxides modified TiO2system with efficient photocatalytic H2production which can provide some insightful understanding for bimetallic metal oxides co-catalyst design and H2evolution mechanism.