SnO₂/ZnO Composite Hollow Nanofiber Electrocatalyst for Efficient CO₂ Reduction to Formate

Abstract

Electrocatalytic reduction of CO2 to formate has become one way to increase the value of CO2 and to overcome the climate change issue. Novel catalysts for the critical role of enhancing reaction selectivity have been continuously explored to provide the best performance. Lately, composite materials have drawn much attention because the synergistic effect between the components provides enhanced physical and chemical properties. Here, we present a highly efficient CO2 reduction reaction to formate on a tin­(IV) oxide/zinc oxide (SnO2/ZnO) composite electrocatalyst with a grainy hollow nanofiber (HNF) structure. The faradaic efficiency (FE) of formate on the SnO2/ZnO composite HNF reaches as high as 97.9% at −1.34 V vs reversible hydrogen electrode (RHE), outperforming many tin-based catalysts. At −1.54 V (vs RHE), the SnO2/ZnO HNF exhibits 2 times and 4 times higher current density for formate generation than those of SnO2 HNF and nanoparticles (NPs), respectively. This superior catalytic performance is attributed to its one-dimensional continuous structure as well as to the synergistic effects between SnO2 and ZnO, which facilitate faster electron transfer and improve the conductivity of SnO2/ZnO composite HNF.

Photoelectrochemical CO2 Reduction Products Over Sandwiched Hybrid Ga2O3:ZnO/Indium/ZnO Nanorods

“…Several reasons were plausibly proposed. In the present study, we used a 2 mm thick Zn plate different from those (e.g., powder in carbon paste) in the literature (Sekimoto et al, 2016;Tatsumi et al, 2017;Kikkawa et al, 2018;Lu et al, 2018;Qin et al, 2018;Yamamoto et al, 2018;Zhang et al, 2018;Liu et al, 2019;Ma et al, 2019;Murali et al, 2019;Zhang et al, 2019;Akatsuka et al, 2020;Daiyan et al, 2020;Hou et al, 2020;Luo et al, 2020;Tan et al, 2020;Yang et al, 2020;Deng et al, 2021;Li et al, 2021;Liang et al, 2021;Ma et al, 2021;Teng et al, 2021;Wang et al, 2021;Wei et al, 2021;Wu et al, 2021;Xiao et al, 2021;Yoon et al, 2021). Therefore, non-Faradaic current such as capacitive current might be significantly involved.…”

“…Electrochemical CO 2 reduction is a promising method, and the development of electrodes is a major goal for approaching practical application in the industry. Among many materials such as pure metals and metal oxides, ZnO, indium (In), and Ga 2 O 3 show very unique CO 2 reduction products after electrochemical reaction (Sekimoto et al, 2016;Tatsumi et al, 2017;Kikkawa et al, 2018;Lu et al, 2018;Qin et al, 2018;Yamamoto et al, 2018;Zhang et al, 2018;Liu et al, 2019;Ma et al, 2019;Murali et al, 2019;Zhang et al, 2019;Akatsuka et al, 2020;Daiyan et al, 2020;Hou et al, 2020;Luo et al, 2020;Tan et al, 2020;Yang et al, 2020;Deng et al, 2021;Li et al, 2021;Liang et al, 2021;Ma et al, 2021;Teng et al, 2021;Wang et al, 2021;Wei et al, 2021;Wu et al, 2021;Xiao et al, 2021;Yoon et al, 2021).…”

Perspective on Nanofiber Electrochemical Sensors: Design of Relative Selectivity Experiments

“…When a nanofiber material, or any other material, shows catalytic activity for an analyte of interest, the nanofiber material has potential to be used as an electrocatalytic sensor for that analyte. Due to the uniquely electroactive characteristics of nanofibers, derived from their large and adjustable active surface area, there is potential for their use in a variety of electrocatalytic applications [62][63][64][65][66][67]. The electrocatalytic behavior of nanofibers can also be tuned by altering their size or configuring their structure, changing the sensitivity and selectivity towards a target analyte [68][69][70].…”

ZnSn nanocatalyst: Ultra-high formate selectivity from CO2 electrochemical reduction and the structure evolution effect

“…Tin (Sn) is a typical catalyst for selective formation formate from eCO 2 RR due to its moderate binding energy to *OCHO [10,41,42], as well as its lower cost and abundant supply [43]. A high formic acid selectivity of 97.9% at −1.34 V vs. reversible hydrogen electrode (RHE) was achieved using a SnO 2 /ZnO composite catalyst [44].…”