Graphene-wrapped Pt/TiO2 photocatalysts with enhanced photogenerated charges separation and reactant adsorption for high selective photoreduction of CO2 to CH4
Graphene-wrapped Pt/TiO2 photocatalysts with enhanced photogenerated charges separation and reactant adsorption for high selective photoreduction of CO2 to CH4
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DOI：
10.1016/j.apcatb.2017.12.071
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发表时间：
2018-06
期刊：
影响因子：
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通讯作者：
Yilong Zhao;Yuechang Wei;Xingxing Wu;Huiling Zheng;Zhen Zhao;Jian Liu;Jianmei Li
中科院分区：
文献类型：
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作者：
Yilong Zhao;Yuechang Wei;Xingxing Wu;Huiling Zheng;Zhen Zhao;Jian Liu;Jianmei Li
人工光合作用将CO2选择性转化为CH 4的效率取决于光催化剂的光生电荷分离和反应物吸附性能。在这里，我们报告了一种新的核-壳结构的光催化剂的Pt/TiO 2-纳米晶体包裹还原氧化石墨烯（rGO）片（（Pt/TiO 2）@rGO）的制造。具有{001}和{101}晶面的超细TiO 2纳米晶作为光生电荷的喷泉，具有很好的光生电荷的吸收能力。Pt纳米粒子沉积在TiO 2纳米晶上，可以聚集和转移来自Pt纳米晶的受激电子。TiO 2-Pt（核）-Pt（介体）-rGO（壳）纳米结的全固态电子多重透射（EMT）系统不仅有利于TiO 2 → Pt → rGO的矢量电子转移，提高光生电子和空穴的分离效率，而且包裹rGO片层的表面残留羟基和扩展π键也能提高对CO2反应物的吸附和活化能力。(Pt/TiO 2）@rGO三元光催化剂表现出优异的多电子选择性光催化转化CO2为CH 4的性能。在所制备的催化剂中，（Pt/TiO 2）@rGO-2催化剂表现出最高的光催化活性和CO2转化选择性，即，CH 4的生成速率为41.3 μmol g−1h− 1，CO2转化为CH 4产物的选择性为99.1%，CH 4产物的表观量子效率为1.93%。作为一种启发，核-壳结构的（Pt/TiO 2）@rGO光催化剂的制备将激发更多新颖的想法应用于光化学能量转换。
Artificial photosynthesis efficiency for selective CO2conversion to CH4as chemical energy-rich molecule is dependent on the photogenerated charges separation and reactant adsorption property of photocatalyst. Here we report a novel fabrication of core-shell-structured photocatalysts of Pt/TiO2-nanocrystals wrapped by reduced graphene oxide (rGO) sheets ((Pt/TiO2)@rGO). The ultrafine anatase TiO2nanocrystals with coexposed {001} and {101} facets acted as the fountain of the photogenerated charges primitively. Pt nanoparticles (NPs) deposited on the TiO2nanocrystals can gather and transfer the stimulated electrons originated from anatase TiO2nanocrystals. The all-solid-state electron multiple transmission (EMT) system with TiO2-nanocrystal(core)-Pt(mediator)-rGO(shell) nanojunction is not only favorable to the vectorial electron transfer of TiO2→ Pt → rGO and enhance the separation efficiency of photogenerated electrons and holes, but also the surface residual hydroxyl and extended π bond of wrapping rGO sheets can improve the adsorption and activation capabilities for CO2reactant. (Pt/TiO2)@rGO ternary photocatalysts exhibit excellent performance for the multi-electron process of selective photocatalytic CO2conversion to CH4. Among the prepared catalysts, (Pt/TiO2)@rGO-2 catalyst shows the highest photocatalytic activity and selectivity for CO2conversion, i.e., the formation rate of CH4is 41.3 μmol g−1h−1and the selectivity of CO2conversion to CH4product is 99.1%, and its apparent quantum efficiency for CH4product is 1.93%. As a heuristic the fabrication of core-shell structured (Pt/TiO2)@rGO photocatalysts will stimulate more novel ideas for application to light-chemical energy conversion.