Novel double-layer core-shell photocatalyst CdS-TiO2@NH2-MIL-101: enhanced conversion of CO2 and CH4 at ambient temperature

Abstract

The conversion of CO2 and CH4 into high value-added chemical products by chemical means is regarded as an emerging industrial technology to solve the increasingly serious climate and energy crises. The solar-powered conversion of CO2 and CH4 to syngas is one such technology that holds promise for the production of renewable fuels. Here, ternary core-shell CdS-TiO2@NH2-MIL-101 composites were prepared using mild experimental methods and their physical and chemical properties were studied using a series of characterization methods. In addition, the interaction between the coupling of different mass fractions of MOF, TiO2, and CdS and the performance of photocatalytic, photothermal, and thermocatalytic CH4 reforming were investigated. The results show that the yields of CO and H2 of the CdS-TiO2@NH2-MIL-101 catalyst at room temperature are 364.46 μmol g−1 and 100.43 μmol g−1, respectively, which are 1200-1500% of the catalytic performance of TiO2. Moreover, the yields of CO and H2 of the CdS-TiO2@NH2-MIL-101 material at 150 °C are 2831.55 μmol g−1 and 1448.20 μmol g−1, respectively. Based on isotope tracer experiments and CO2 adsorption experiments, a possible comprehensive mechanism for CdS-TiO2@NH2-MIL-101 photocatalytic CH4 reforming is proposed. In addition to presenting a fresh research concept for achieving carbon neutrality, this work offers a new technical pathway for the quick conversion of CO2 and CH4 at room temperature.