Cobalt−Iron Oxide Nanosheets for High‐Efficiency Solar‐Driven CO₂−H₂O Coupling Electrocatalytic Reactions

Abstract

Solar‐driven electrochemical overall CO2 splitting (OCO2S) offers a promising route to store sustainable energy; however, its extensive implementation is hindered by the sluggish kinetics of two key reactions (i.e., CO2 reduction reaction and oxygen evolution reaction (CO2RR and OER, respectively)). Here, as dual‐functional catalysts, Co2FeO4 nanosheet arrays having high electrocatalytic activities toward CO2RR and OER are developed. When the catalyst is applied to a complete OCO2S system driven by a triple junction GaInP2/GaAs/Ge photovoltaic cell, it shows a high photocurrent density of ≈13.1 mA cm−2, corresponding to a remarkably high solar‐to‐CO efficiency of 15.5%. Density functional theory studies suggest that the Co sites in Co2FeO4 are favorable to the formation of *COOH and *O intermediates and thus account for its efficient bifunctional activities. The results will facilitate future studies for designing highly effective electrocatalysts and devices for OCO2S.

Metal‐Free Multi‐Heteroatom‐Doped Carbon Bifunctional Electrocatalysts Derived from a Covalent Triazine Polymer

“…The ever-increasing energy demand promotes the vigorous exploitation of advanced and green energy techniques, such as rechargeable metal-air batteries, fuel cells, water electrolysis technologies, etc. [1][2][3][4][5][6][7][8][9] However, the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) during discharge and charge processes has severely hampered their widespread applications. [10,11] Efficient electrocatalysts are required to accelerate ORR and OER.…”

Two‐Terminal Perovskite‐Based Tandem Solar Cells for Energy Conversion and Storage

“…The three-junction GaInP 2 /GaAs/Ge solar cells are commonly used for driving elements, accompanying by a sufficient V OC of 2.5 V and a high J SC greater than 14 mA cm −2 . [113] In the tandem solar cell-driven system, the operating current was observed to be 13.1 mA cm −2 from the intersection point, hence the solar-to-CO efficiency reached 15.5%, very close to the maximum power point for the solar-to-electric energy conversion, shown as Figure 12c,d. Recently, Tan et al report an all-perovskite triple-junction solar cells with PCEs over 20% and V OC up to 2.80 V. [114] Simultaneously, Janssen and coworkers present a triple-junction perovskite tandem, showing very promising PCE of 16.8%, with a V OC of 2.78 V. [115] Given the rapid progress in triple-junction perovskite tandem cells, it is anticipated that the perovskite-driven conversion of carbon dioxide with high efficiency and low cost could be achieved in the near future.…”

“…Reproduced with permission. [113] Copyright 2020, Wiley.…”

“…c) Schematic diagram; d) J−V curves of the GaInP 2 /GaAs/Ge tandem solar cell under simulated AM 1.5 G 1 Sun solar irradiation. Reproduced with permission [113]. Copyright 2020, Wiley.…”

Metal‐Free Bifunctional Ordered Mesoporous Carbon for Reversible Zn‐CO2 Batteries

“…[ 1,2 ] Great efforts are devoted to developing renewable and eco‐friendly strategies for CO 2 utilization. [ 3–9 ] As a newly viable technology, rechargeable metal‐CO 2 batteries, combining anodic metal with cathodic CO 2 reduction to mimic artificial photosynthesis, can realize sustainable electricity supplement and value‐added chemical production simultaneously. [ 9–11 ] However, current nonaqueous metal‐CO 2 batteries (such as Li/Na‐CO 2 batteries) still suffer from some disadvantages: the low operating voltages and energy densities caused by the low theoretical capacity of active anodes; environment contamination relating to the nonaqueous electrolytes, such as gel polymer/ionic liquid electrolyte.…”