MOFs-derived C-In2O3/g-C3N4 heterojunction for enhanced photoreduction CO2

Converting carbon dioxide into valuable chemicals is seen as a promising strategy for slowing global warming while enriching energy supplies. Photocatalysts derived from Metal-Organic Frameworks (MOFs) can not only overcome the problem of poor stability of MOFs, but also inherit the advantages of MOFs to some extent. Herein, carbon doped In2O3 (C-In2O3) hollow tubular is synthesized by calcination of MIL-68(In) as sacrificial template. Then C-In2O3 and g-C3N4 are hydrothermal to obtain C-In2O3/g-C3N4 heterojunction. The unique hollow tubular structure, carbon doping and type-II heterojunction of C-In2O3/g-C3N4 expand the light absorption capacity and promote the separation of photogenerated electron-hole pairs, thus significantly improve the activity of photocatalytic reduction of CO2. Among them, C-In2O3/g-C3N4-5 shows the highest CO2 reduction activity towards CO (153.42 μmol/g/h) and CH4 (110.31 μmol/g/h). Type-II heterojunction of C-In2O3/g-C3N4 achieve highly CO2 photocatalytic conversion to CO and CH4. In addition, the doped C element in In2O3 accelerates the transmission efficiency of photogenerated carriers and its tubular structure enhances the absorption of light, both of which are conducive to improving the performance of photocatalytic reduction of CO2. [Display omitted] •Using MIL-68(In) as a template, C-doped tubular In2O3 was obtained by pyrolysis.•The obtained photocatalyst can achieve efficient photocatalytic conversion of CO2 to CO and CH4.•C-In2O3/g-C3N4 type-II heterojunction can hinder electron-hole recombination and boost charge transfer.