Converting CO₂ into Value‐Added Products by Cu₂O‐Based Catalysts: From Photocatalysis, Electrocatalysis to Photoelectrocatalysis

Abstract

Considering the high energy demand in modern society and the widespread acceptance of "carbon neutrality" policies, reducing CO 2 into value-added products through "artificial carbon cycling" seems more reasonable and attractive. [3,4] Among the various methods of CO 2 resource utilization, photocatalysis (PC), electrocatalysis (EC) and photoelectrocatalysis (PEC), which can be operated at room temperature and atmospheric pressure, are considered to be a relatively feasible scheme. [5][6][7][8][9] Photocatalysis based on semiconductor materials can directly absorb solar light and generate charge carriers with redox capability, simultaneously accomplishing energy storage and carbon reduction. [10][11][12][13] Electrocatalysis can be driven by multiple forms of renewable energy (solar energy, water energy, wind energy, biomass energy, wave energy, tidal energy, etc.) to realize the conversion of CO 2 at the suitable negative potential. [14][15][16] Photo electrocatalysis is a special combination of photocatalysis and electrocatalysis, using a semiconductor electrode with light response capability to achieve efficient CO 2 reduction. [17,18] However, CO 2 exhibits chemical inertness due to its linear molecular and high CO bond energy, which is owing to the adoption of sp hybrid orbital when C atoms bond with O atoms. [19][20][21] Therefore, it is challenging to activate CO 2 and convert it into desirable products thermodynamically. [22] In addition, the CO 2 reduction reaction involves multi-step electron transfer, hydrogenation and CC bond coupling, which determines it has a complex and stochastic reaction path. Therefore, developing an ideal catalyst with high activity, stability, and economy for CO 2 reduction is necessary.Since Inoue et al. successfully converted CO 2 into formic acid, formaldehyde, methanol and methane under sunlight irradiation, many semiconductor materials for CO 2 reduction have been developed and evaluated. [23][24][25][26] The n-type semiconductors, including TiO 2 , ZnO 2 and SrTiO 3 , have attracted wide attention due to their low cost, high photostability and environmental harmlessness. [27] However, the excessive band gap limits their light response range, making them unsuitable for the CO 2 conversion systems driven by solar light. [28,29] Cuprous oxide (Cu 2 O), as one of the copper-based semiconductors with abundant reserves on the earth, has a suitable band gap to absorb visible light, which occupies 42-43% of the solar spectrum. More Converting CO 2 into value-added products by photocatalysis, electrocatalysis, and photoelectrocatalysis is a promising method to alleviate the global environmental problems and energy crisis. Among the semiconductor materials applied in CO 2 catalytic reduction, Cu 2 O has the advantages of abundant reserves, low price and environmental friendliness. Moreover, Cu 2 O has unique adsorption and activation properties for CO 2 , which is conducive to the generation of C 2+ products through CC coupling. This review introduces the basic principles of CO...

A dual Z-scheme heterojunction Cu-CuTCPP/Cu2O/CoAl-LDH for photocatalytic CO2 reduction to C1 and C2 products

“…26 The construction of heterojunctions to promote the rapid recombination of photogenerated electrons and holes in Cu 2 O is undoubtedly an effective method to prevent the photocorrosion reaction. 27 Dong et al 28 successfully synthesized a Co-MOF/Cu 2 O heterojunction based on Co-MOF and nanocrystalline Cu 2 O. The optimum photocatalytic activity of Co-MOF/Cu 2 O was about 9.6 times higher than that of pristine Cu 2 O, which provides inspiration for the design of the catalyst in this research.…”

Modular preparation of functional bimetallic spinels from metal–organic frameworks: a deep exploration from macro and micro perspectives

“…These not only destroy the ecological environment, but even pose a great threat to biological life. 162,163 Based on the above, the treatment and monitoring of various pollutants has become an important part of the green and sustainable development of ecological environment protection. 164–166 MOF-derived bimetallic spinels have become one of the dominant catalysts for the degradation and monitoring of pollutants due to their excellent size, structure, and tunable composition.…”

Recent Progress and Outlook of Metal–Organic Framework Materials Used for CO2 Electrocatalytic Reduction

“…Generally, MOF materials encompass the combined functionalities of both metal ions and clusters and organic ligands. By synergistically coupling the electronic, magnetic, and optical properties of inorganic and organic structural units, it becomes possible to create MOF materials with enhanced functionality and broader applicability. − …”