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Photoelectrocatalytic CO2 reduction to ethanol via graphite-supported and functionalized TiO2 nanowires photocathode

2020; Elsevier BV; Volume: 391; Linguagem: Inglês

10.1016/j.jphotochem.2020.112368

1873-2666

Liwen Wang, Wei Yan, Ran Fang, Jinyuan Wang, Xiaogang Yu, Jiazang Chen, Huanwang Jing,

Covalent Organic Framework Applications

The photoelectrocatalytic CO2 reduction into value-added carbon-based energetic molecules is a promising strategy to store solar energy into chemicals, which lessen the concentration of atmospheric contamination. In this study, the graphitic supported and multiple functionalized nanowire TiO2 semiconductor was firstly used to CO2 reduction with water under photoelectrocatalytic conditions. These photocathodes of R-TiO2@GS were designed to be functionalized by organic ligands that catch CO2 and control the C-C coupling as the Calvin cycle in natural plants. These new organic–inorganic composite electrodes were facile to be prepared and well characterized by using NMR, UV–vis, FTIR, PL, TRPL, EIS and XPS spectra; XRD patterns; SEM, TEM images. The transient absorption spectra of photocathodes demonstrate the efficiency of electron transfer between the Eosin Y and semiconductor, ensuring CO2 reduction. Their Mott–Schottky plots show that the flat band potentials are improved by organic ligands, favoring the ethanol production. The light quantum efficiency of the best photoelectrocatalytic cell of S-TiO2@GS│SCE│Pt reaches to 1.0 % that is 2 times better than natural plant. To better understand the working process of the photoelectrocatalytic cell, a plausible mechanism of CO2 reduction in water was carefully proposed as well.