Controlled Preparation of Cross-Linked SnO2 Hollow Nanotube Networks for Electrocatalytic CO2 Reduction

The electrochemical system based on water, CO2, and electricity is the key technology to realize the coexistence and combination of renewable energy and fossil energy, which can convert CO2 molecules into high-value-added products under mild and controlled conditions, thus achieving carbon neutrality. Designing efficient electrocatalysts to realize highly active, selective, and stable CO2RR has become one of the vital issues. Particularly, the nanostructure design and interface adjustment of electrocatalysts have been regarded as the key points for improving their catalytic performance. Herein, a tin dioxide hollow nanotube (SnO2 HNT) catalyst with a three-dimensional cross-linked network structure has been fabricated by electrospinning and rapid-heating calcination. The morphology and component structure of SnO2 HNTs were analyzed by a series of characterizations. The performance in electrocatalytic carbon dioxide reduction reaction (eCO2RR) was further tested. Owing to the hollow nanostructure, the catalyst possessed a large specific surface area and abundant active sites, which greatly accelerated mass transport and electron mobility. During eCO2RR, SnO2 HNTs achieved a peak faraday efficiency value of 87.4% for C1 products at −1.1 V vs RHE, which significantly suppressed the occurrence of hydrogen evolution side reactions. In addition, compared with the commercial SnO2 nanoparticles or partially reduced Sn/SnO2, the catalytic activity and selectivity of CO2-to-formate conversion significantly increased under the same potential, indicating that the optimization of electronic/geometric structure for high-yield metal oxides can effectively improve the comprehensive performance of eCO2RR.