. Different CO₂ adsorption modes on the surface of photocatalysts^[4]

. Possible reaction paths for CO₂ reduction to produce HCHO, CH₃OH, and CH₄^[35,36]

. Possible reaction paths for CO₂ reduction to produce C₂H₄, CH₃CHO, and C₂H₅OH^[35]

. (a) Calculated band positions of the WO₃ nanosheet and commercial WO₃, relative to the redox potential of CO₂/CH₄ in the presence of water, and (b) CH₄ generation over the nanosheet and commercial powder as a function of visible light irradiation time (λ≥420 nm)^[38]

. Height images of (a) atomically thin InVO₄ nanosheet, (b) nanocube, and (c) bulk materials obtained by conventional solid-state reaction, surface photovoltage spectroscopy (SPV) images in (a′), (b′), and (c′) displaying differential images between potential images under light and in the dark, and (d) surface photovoltage change by subtracting the potential under dark conditions from that under illumination (SPV, ΔCPD = CPD_dark - CPD_light)^[13]

. Band structures of PCMT@In₂O₃/ZIS^[47]

. Photocatalytic (a) CO and (b) CH₄ output changing with light irradiation time, (c) comparison of photocatalytic activity over different samples, (d)schematic illustration of the photocatalytic CO₂ reduction for ZnIn₂S₄/BiVO₄ nanocomposite, schematic representation of (e) Z-scheme electron-hole transfer mechanisms, and (f) heterojunction-type electron-hole transfer mechanisms under light irradiation^[50]

. TEM images of (a, b) poly(methylmethacrylate) spheres coated with (protonic polyethylenimine (PEI)/Ti_0.91O₂/ PEI/GO)₅, (c, d) (G-Ti_0.91O₂)₅ hollow spheres, and (e)comparation of the average product formation rates^[53]

. (a, b) SEM images of InVO₄/Ti₃C₂T_x at higher magnification, (c) HRTEM images of InVO₄/Ti₃C₂T_x, (d)scheme for spatial charge separation and transport during the photocatalytic reduction of CO₂ over hierarchical InVO₄/Ti₃C₂T_x heterosystem, and (e)energy level alignment of InVO₄/Ti₃C₂T_x hybrid^[56]

. Schematic illustration of the preparation procedure of the Au-TiO₂ composites (b), schematic illustration of charge separation and transfer in the Au-TiO₂ system and photoreduction of CO₂ into different products^[57]

. (a) Scheme of the electronic band structures of Vo-rich WO₃ atomic layers and WO₃ atomic layers, and (b) in situ FT-IR spectra for the IR light-driven CO₂ reduction process on the Vo-rich WO₃ atomic layers^[60]

Table 1. Standard potentials of convert CO₂ to various C₁ and C₂ products in aqueous solutions at standard conditions (1.01×10⁵ Pa and 25 ℃) ^[34]