Photocatalytic Reduction of Carbon Dioxide by Hydrous Hydrazine over Au–Cu Alloy Nanoparticles Supported on SrTiO₃/TiO₂ Coaxial Nanotube Arrays

Abstract

Efficient photocatalytic conversion of CO2 into CO and hydrocarbons by hydrous hydrazine (N2H4⋅H2O) is achieved on SrTiO3/TiO2 coaxial nanotube arrays loaded with Au-Cu bimetallic alloy nanoparticles. The synergetic catalytic effect by the Au-Cu alloy nanoparticles and the fast electron-transfer in SrTiO3/TiO2 coaxial nanoarchitecture are the main reasons for the efficiency, while N2H4⋅H2O as the H source and electron donor provides a reducing atmosphere to protect the surface Cu atoms from oxidation, therefore maintaining the alloying effect which is the basis for the high photocatalytic activity and stability. This approach opens a feasible route to enhance the photocatalytic efficiency, which also benefits the development of photocatalysts and co-catalysts.

Photoreduction of CO2 on ZIF-8/TiO2 nanocomposites in a gaseous photoreactor under pressure swing

“…[1] Since then over 130 types of photocatalytically active materials have been developed and tested in various liquid and gaseous photo-reactors [2,3]. The photocatalytic process is a complex, multi-step surface redox reaction initiated by electron-hole separation and transfer derived from the semiconducting characteristics of the catalyst materials [4]. For CO2 reduction on catalysts, CO2 electron affinity is relatively high (-1.9 eV) which is lowered when it disorients from its stable liner structure into a less stable bent structure upon adsorption [5].…”

Recent progress on advanced design for photoelectrochemical reduction of CO2 to fuels

“…3b). In addition, some other pathways involving C-C coupling (e.g., glyoxal pathway) were also reported and investigated, which might induce more complicated products [57]. The products are sensitively influenced by photocatalysts and external environments during the processes of reduction, forming a grand challenge for optimizing the selectivity of CO 2 reduction.…”

Metal/Semiconductor Hybrid Nanocrystals and Synergistic Photocatalysis Applications

“…Nowadays, several series of semiconductor have been used for photoreduction of CO 2 , such as oxides [126,[131][132][133], sulfides [134], phosphide [135][136], and so on. In most case, metal will be used as cocatalysts to enhance photoreduction efficiency.…”