TiO_2-Ti_3C_2 Composites with Pt Decoration as Efficient Photocatalysts for Ethylene Oxidation under Near Infrared Light Irradiation

Efficient utilization of solar energy is highly desirable in the field of photocatalysis. However, the near-infrared part of the solar spectrum, which constitutes about 44% of sunlight, has rarely been used. Herein, we report that the TiO_2 coupled with MXene Ti_3C_2 nanosheets shows promising photoactivity for ethylene oxidation under near infrared light(NIR) irradiation. Moreover, the Pt nanoparticle decoration can dramatically improve the performance of TiO_2–Ti_3C_2 nanocomposites. Within 15 minutes irradiation of the NIR light, 444 ppm of C_2 H_4 is completely removed over 1 wt%Pt–TiO_2–Ti_3C_2 and the catalyst exhibits excellent stability. It is expected that our work could provide useful information for the design and synthesis of efficient and stable NIR active photocatalyst for the target applications.     

Fabrication of WO_3/TiO_2 Heterostructures for Efficiently Photocatalytic Gaseous Hydrocarbons Degradation: Origin of Photoactivity and Revisit the Role of WO_3 Decoration

Efficient oxidation of gaseous small molecular hydrocarbons under mild conditions remains a significant but challenging task to date.Here we report that WO_3 decoration can obviously improve the performance of Ti O_2(P25)toward the photocatalytic oxidation of several small molecular hydrocarbons(C_2H_6,C_3H_8 and C_2H_4)under simulated solar light irradiation.Among the WO_3/Ti O_2 heterostructures,the 10wt%WO_3/Ti O_2 nanocomposite shows the best photoactivities,which can efficiently oxidize C_2H_6,C_3H_8 and C_2H_4 within 15,9 and 8 minutes,respectively under simulated sunlight with a light intensity of 200 m W/cm~2.By strong contrast,a decreased photoactivity of Ti O_2 by coupling with WO_3 is observed when investigating the performance of photocatalysts toward the degradation of methylene blue(MB)in liquid phase.The opposing effect of WO_3 decoration on the performance of Ti O_2 is thoroughly investigated,and it is found that the improved photoactivities for gaseous hydrocarbon degradation is ascribed to the enhanced oxygen adsorption,resulting from WO_3 decoration rather than efficient charge separation within the WO_3/Ti O_2 heterostructures.     

光催化选择性氧化还原体系在有机合成中的研究进展

21世纪,化学研究的一个主要目标是发展一种高效能技术,用于取代那些对环境有害的耗能过程.光催化选择性氧化还原体系的出现和应用极大地满足了人们对能源和环境的要求.在光催化选择性氧化还原体系中,反应发生所需要的条件比传统催化温和,同时它也避免了一些强氧化剂和危险还原性物质的使用,通过优化反应环境可以实现对某种目标产物的高选择性,从而为有机合成提供了一种绿色、节能的途径,成为21世纪最具潜力的绿色有机化学技术.本文重点阐述了光催化选择性氧化还原体系在有机合成领域中的重要进展,并对其存在的问题及相关领域的发展趋势作了展望.