Search

High-rate electrolysis of CO2 to C2+ alcohols is of particular interest, but the performance remains far from the desired values to be economically feasible. Coupling gas diffusion electrode (GDE) and 3D nanostructured catalysts may improve the efficiency in a flow cell of CO2 electrolysis. Herein, we propose a route to prepare 3D Cu-chitosan (CS)-GDL electrode. The CS acts as a “transition layer” between Cu catalyst and the GDL. The highly interconnected network induces growth of 3D Cu film, and the as-prepared integrated structure facilitates rapid electrons transport and mitigates mass diffusion limitations in the electrolysis. At optimum conditions, the C2+ Faradaic efficiency (FE) can reach 88.2% with a current density (geometrically normalized) as high as 900 mA cm−2 at the potential of −0.87 V vs. reversible hydrogen electrode (RHE), of which the C2+ alcohols selectivity is 51.4% with a partial current density of 462.6 mA cm−2, which is very efficient for C2+ alcohols production. Experimental and theoretical study indicates that CS induces growth of 3D hexagonal prismatic Cu microrods with abundant Cu (111)/Cu (200) crystal faces, which are favorable for the alcohol pathway. Our work represents a novel example to design efficient GDEs for electrocatalytic CO2 reduction (CO2RR).

A porous Ce/TiO2 composite exhibiting high photocatalytic activity was successfully prepared by a sol–gel method using β-cyclodextrin (β-CD) polymer microspheres as the template. The structural and morphological characteristics of the prepared Ce/TiO2 composites were examined by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, low-temperature N2 adsorption–desorption, thermogravimetry–differential thermal analysis, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The characterization results revealed that after the calcination of as-prepared Ce/TiO2 at 500 °C, it exhibits a porous structure with a TiO2 anatase phase. The photocatalytic performance of the as-prepared samples according to their different molar ratios was evaluated toward the degradation of rhodamine B (RhB). Compared to commercial TiO2, the porous Ce/TiO2 composite exhibited a higher photocatalytic activity under visible light irradiation at room temperature, with a photodegradation rate of up to 80% for RhB (5 mg L−1) within 60 min. Addition of β-cyclodextrin polymer microspheres as the template not only renders a porous structure but also inhibits the crystal growth and anatase-to-rutile transformation of TiO2. Doping with Ce was hypothesized to decrease the radiative recombination of the photogenerated electrons and holes in TiO2, extending its light response to the visible region.