Self-assembly of nitrogen-doped TiO2 with exposed {001} facets on a graphene scaffold as photo-active hybrid nanostructures for reduction of carbon dioxide to methane

明确的锐钛矿 TiO 的定制的合成 < 潜水艇 class= “ a-plus-plus ” > 2 -based 晶体与暴露 { 001 } 方面刺激了由于他们的科学、工艺的重要性世界范围的连续研究兴趣。此处，锐钛矿做氮的 TiO <潜水艇class=“ a-plus-plus ”> 2 ( N-TiO <潜水艇class=“ a-plus-plus ”> 2 ) nanoparticles 与暴露{ 001 }方面在 graphene ( GR )上扔了表( N-TiO <潜水艇class=“ a-plus-plus ”> 2 -001/GR)第一次被综合经由一步舞 solvothermal 用 NH 的合成线路<潜水艇class=“ a-plus-plus ”> 4 F 作为控制形态学的代理人。试验性的结果例示那 GR 一致地被锐钛矿 N-TiO 盖住 < 潜水艇 class= “ a-plus-plus ” > 2 nanoparticles (1017 nm ) ，暴露 { 001 } 方面。百分比暴露 { 001 } 在 N-TiO 的方面 < 潜水艇 class= “ a-plus-plus ” > 2 -001/GR nanocomposites 被计算是 ca。35% 。另外，在吸收边的红移动和在可见轻范围的强壮的吸收由于 Ti-O-C 契约的形成被观察，导致从 3.23 ～ 2.9 eV 的乐队差距的成功的变窄。同样准备的光催化剂的 photocatalytic 活动为公司被评估<潜水艇class=“ a-plus-plus ”>生产 CH 的 2 减小<潜水艇class=“ a-plus-plus ”> 4 面对在周围的温度和气压用下面的水蒸汽一低力量 15 W 节省精力的日光灯作为可见到最通常采用的高力量的氙 lampswhich 的轻 sourcein 对比经济地并且实际上显示了这个过程可行。在所有学习光催化剂之中， N-TiO < 潜水艇 class= “ a-plus-plus ” > 2 -001/GR nanocomposites 展出了最大的 CH < 潜水艇 class= “ a-plus-plus ” > 3.70 摩尔的 4 产量？？

Tailored synthesis of well-defined anatase TiO2-based crystals with exposed {001} facets has stimulated incessant research interest worldwide due to their scientific and technological importance. Herein, anatase nitrogen-doped TiO2 （N-TiO2） nanoparticles with exposed {001} facets deposited on the graphene （GR） sheets （N-TiO2-001/GR） were synthesized for the first time via a one-step solvothermal synthetic route using NH4F as the morphology-controlling agent. The experimental results exemplified that GR was uniformly covered with anatase N-TiO2 nanoparticles （10-17 nm）, exposing the {001} facets. The percentage of exposed {001} facets in the N-TiO2-001/GR nanocomposites was calculated to be ca. 35%. Also, a red shift in the absorption edge and a strong absorption in the visible light range were observed due to the formation of Ti-O-C bonds, resulting in the successful narrowing of the band gap from 3.23 to 2.9 eV. The photocatalytic activities of the as-prepared photocatalysts were evaluated for CO2 reduction to produce CH, in the presence of water vapor under ambient temperature and atmospheric pressure using a low-power 15 W energy-saving daylight lamp as the visible light source--in contrast to the most commonly employed high-power xenon lamps--which rendered the process economically and practically feasible. Among all the studied photocatalysts, the N-TiO2-001/GR nanocomposites exhibited the greatest CH4 yield of 3.70 p-mol＇gcatalyst 1, approxi- mately 11-fold higher activity than the TiO2-001. The enhancement of photocatalyfic performance was ascribed to the effective charge anti-recombination of graphene, high absorption of visible light region relative to the {101} facets. and high catalytic activity of {001} facets