Carbon dots anchored NiAl-LDH@In_(2)O_(3) hierarchical nanotubes for promoting selective CO_(2) photoreduction into CH_(4)

The efficient conversion of CO_(2) into hydrocarbon fuels(CH_(4))with high selectivity is considered as a great challenge in photocatalysis owing to the multiple-electron transfer pathway and competitive H_(2) generation.Herein,we developed carbon dots(CDs)-modulated S-scheme heterojunction of CDs/NiAl-LDH@In_(2)O_(3)(C-DH@IN)through a facile in-situ hydrothermal method.Thanks to the multi-shell nanotube structure,the C-DH@IN shows an enhanced CH_(4) evolution rate of 10.67μmol h^(-1)g^(-1)and higher selectivity of CH_(4)(85.70%)compared with In_(2)O_(3) and Ni Al-LDH@In_(2)O_(3) binary catalyst in the pure water without sacrificial agent.Electron spin resonance(ESR)and in situ Fourier transform infrared spectra verify that the constructed S-scheme heterojunction can possess the strong redox capability and the HCOOand CH_(3)O-as critical intermediates play an important role in selective CO_(2) reduction to generate CH_(4).Furthermore,CDs with superior photoabsorption can boost the electron transfer and absorb H^(+),thus improving the integration of H^(+)and CO_(2) molecule.Therefore,this work emphasizes a facile strategy to achieve efficient CO_(2)-to-CH_(4) conversion based on construction of CDs-based heterojunction catalysts.