Advanced Materials Research Unit, Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, 10520 Ladkrabang, Bangkok, Thailand.
Advanced Materials Research Unit, Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, 10520 Ladkrabang, Bangkok, Thailand.
Ultrason Sonochem. 2019 Nov;58:104657. doi: 10.1016/j.ultsonch.2019.104657. Epub 2019 Jun 22.
Converting CO to usable fuel may contribute to lowering of global warming, thus this study developed effective heterojunction photocatalysts for the photoreduction of CO with water into methanol and ethanol fuels. The photocatalysts were prepared from combining surface modified titanium dioxide (TiO) nanoparticles with reduced graphene oxide (rGO) and cerium oxide (CeO). The TiO surfaces were firstly modified via the sono-assisted exfoliation, with high intensity ultrasonic waves (ultrasonic horn, 20 kHz, 150 W/cm) in 10 M NaOH for 1 h. Highly reactive nanosheets delaminated from outer surfaces of the primary TiO crystals leading to an increase in specific surface active area, light absorption and decrease in electron-hole recombination rate, which enhanced photocatalytic activity. Then, 0.75 wt% rGO and 1 wt% CeO were incorporated into the surface modified TiO to promote photogenerated charge separation, electron mobility and CO absorptivity. The modified TiO/rGO/CeO photocatalysts exhibited superior photocatalytic performance by producing methanol at 641 μmol/gh and ethanol at 271 μmol/gh, almost 7 times higher than rates from pure TiO. The significant improvement in CO photoconversion activity was mainly attributed to the high interfacial contact area and strong connection between the reactive delaminated TiO nanosheets, rGO and CeO, which, in turn, facilitated the flow of large number of photogenerated charge carriers to react with the absorbed species, and the multi-step charge transportation due to the heterojunction effect that effectively retarded electron-hole recombination.
将 CO 转化为可用燃料可能有助于降低全球变暖，因此本研究开发了用于 CO 与水光还原成甲醇和乙醇燃料的有效异质结光催化剂。光催化剂是通过将表面改性的二氧化钛 (TiO) 纳米颗粒与还原氧化石墨烯 (rGO) 和氧化铈 (CeO) 结合制备的。首先通过超声辅助剥离对 TiO 表面进行改性，在 10M NaOH 中使用高强度超声波（超声喇叭，20kHz，150W/cm）处理 1 小时。高反应性的纳米片从初级 TiO 晶体的外表面剥落，导致比表面积、光吸收增加和电子-空穴复合率降低，从而提高了光催化活性。然后，将 0.75wt% rGO 和 1wt% CeO 掺入表面改性的 TiO 中，以促进光生载流子的分离、电子迁移率和 CO 的吸收。改性 TiO/rGO/CeO 光催化剂通过产生 641μmol/gh 的甲醇和 271μmol/gh 的乙醇表现出优异的光催化性能，几乎比纯 TiO 的速率高 7 倍。CO 光转化活性的显著提高主要归因于活性剥离 TiO 纳米片、rGO 和 CeO 之间的高界面接触面积和强连接，这反过来又促进了大量光生载流子与吸收物质反应的流动，并由于异质结效应而发生多步电荷传输，有效地抑制了电子-空穴复合。
