Zhou Xin-Ke, Li Yu, Luo Pei-Pei, Lu Tong-Bu
MOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Materials Science & Engineering, Tianjin University of Technology, Tianjin 300384, China.
ACS Appl Mater Interfaces. 2023 Aug 2;15(30):36280-36288. doi: 10.1021/acsami.3c06376. Epub 2023 Jul 19.
Room-temperature photocatalytic conversion of CH into liquid oxygenates with O/HO provides an appealing route for sustainable chemical industry, which, however, suffers from poor efficiency due to the undesired carrier kinetics and low yield of reactive oxygen species of the currently available photocatalysts. Here, we report an effective surface engineering strategy where concurrent constructions of oxygen vacancies and phosphate sites on TiO nanosheets address the above challenge. The surface oxygen vacancies and phosphates are respective acceptors of photogenerated electrons and holes for promoted separation and migration of charge carriers. Moreover, in addition to the facilitated activation of O to OH by electrons at oxygen vacancies, the surface phosphates also facilely adsorb HO via hydrogen bonds and thus effectively transfer holes to HO for enhanced OH production, thereby boosting CH conversion. As a result, compared with TiO sheets with only oxygen vacancies, a 2.8 times improvement in liquid oxygenate production with near-unity selectivity is achieved by virtue of the synergy of surface oxygen vacancies and phosphate sites, together with an unprecedent quantum efficiency of 19.8% under 365 nm irradiation.
利用O₂/H₂O将CH₄在室温下光催化转化为液态含氧化合物为可持续化学工业提供了一条有吸引力的途径，然而，由于目前可用光催化剂存在不理想的载流子动力学和活性氧物种产率低的问题，该途径效率低下。在此，我们报道了一种有效的表面工程策略，即在TiO₂纳米片上同时构建氧空位和磷酸盐位点，以应对上述挑战。表面氧空位和磷酸盐分别是光生电子和空穴的受体，可促进电荷载流子的分离和迁移。此外，除了通过氧空位处的电子将O₂促进活化成OH⁻外，表面磷酸盐还通过氢键轻松吸附H₂O，从而有效地将空穴转移到H₂O以增强OH⁻的产生，从而促进CH₄转化。结果，与仅具有氧空位的TiO₂片相比，由于表面氧空位和磷酸盐位点的协同作用，液态含氧化合物产量提高了2.8倍，选择性接近100%，并且在365 nm光照下具有19.8%的前所未有的量子效率。
