Hydroxyapatite decorated TiO2 as efficient photocatalyst for selective reduction of CO2 with H2O into CH4
Hydroxyapatite decorated TiO2 as efficient photocatalyst for selective reduction of CO2 with H2O into CH4
复制标题
羟基磷灰石修饰的 TiO2 作为高效光催化剂，用于选择性地将 CO2 与 H2O 还原成 CH4
DOI：
10.1016/j.ijhydene.2018.10.045
复制
发表时间：
2018-12-06
影响因子：
7.2
通讯作者：
Li, Deliang
中科院分区：
文献类型：
--
作者：
Chong, Ruifeng;Fan, Yangyang;Li, Deliang
光催化CO2还原需要具有高选择性的高效催化剂。本研究通过在金红石型TiO2上原位沉积Ca(OH)(2)并进行水热反应，成功制备了羟基磷灰石（HAP）修饰TiO2 （HAP/TiO2）。与TiO2相比，HAP/TiO2在H2O存在下光催化还原CO2的能力显著增强（约40倍），对CH4的选择性为95%左右。表征结果表明，HAP具有Lewis碱性位点（- po43 -基团中的O2-）和Lewis酸性位点（Ca2+或OH-空位），其中Lewis碱性位点能够增强CO2的吸附/活化，Lewis酸性位点能够促进H2O的吸附/解离，从而促进CO2和H2O在Pt/TiO2上的光催化还原和氧化半反应。在HAP/TiO2上形成更稳定的中间体是CH4具有高选择性的原因。此外，光电化学和电化学表征表明HAP还能促进TiO2的电荷分离以及TiO2与吸附物之间的电荷转移。研究结果表明，HAP具有作为H2O光催化CO2还原的高效助手的巨大潜力，并将激励我们设计具有调谐刘易斯酸性和刘易斯碱性位点的新型半导体基材料，以实现高效的光催化剂。(C) 2018氢能源出版有限责任公司，由爱思唯尔有限公司出版。版权所有。
Efficient catalysts with high selectivity in products are highly desirable for photocatalytic CO2 reduction. In this work, hydroxyapatite (HAP) decorated TiO2 (HAP/TiO2) were successfully fabricated via in-situ deposition of Ca(OH)(2) on rutile TiO2 followed by a facile hydrothermal reaction. Comparing with TiO2, HAP/TiO2 exhibited significant enhancement (ca. 40 times) toward photocatalytic CO2 reduction in the presence of H2O with a >95% selectivity of CH4. The characterizations revealed HAP possessed Lewis basic sites (O2- in -PO43- groups) and Lewis acidic sites (Ca2+ or OH- vacancies), where Lewis basic sites could enhance the adsorption/activation of CO2 and Lewis acidic sites facilitated the adsorption/dissociation of H2O respectively, thus promoting the photocatalytic reduction and oxidation half-reactions of CO2 and H2O over Pt/TiO2. The formation of much more stable intermediates over HAP/TiO2 would be responsible for the high selectivity of CH4. Moreover, photoelectrochemical and electrochemical characterizations revealed HAP could also promote the charge separation of TiO2 and the charge transfer between TiO2 and adsorbed species. The findings demonstrate HAP has a great potential as efficient assistant for photocatalytic CO2 reduction with H2O and will stimulate us to design novel semiconductor-based materials with tuned Lewis acidic and Lewis basic sites to achieve highly efficient photocatalysts. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.