Recent Progress of Three-Dimensional Graphene-Based Composites for Photocatalysis

Abstract

Converting solar energy into fuels/chemicals through photochemical approaches holds significant promise for addressing global energy demands. Currently, semiconductor photocatalysis combined with redox techniques has been intensively researched in pollutant degradation and secondary energy generation owing to its dual advantages of oxidizability and reducibility; however, challenges remain, particularly with improving conversion efficiency. Since graphene's initial introduction in 2004, three-dimensional (3D) graphene-based photocatalysts have garnered considerable attention due to their exceptional properties, such as their large specific surface area, abundant pore structure, diverse surface chemistry, adjustable band gap, and high electrical conductivity. Herein, this review provides an in-depth analysis of the commonly used photocatalysts based on 3D graphene, outlining their construction strategies and recent applications in photocatalytic degradation of organic pollutants, H₂ evolution, and CO₂ reduction. Additionally, the paper explores the multifaceted roles that 3D graphene plays in enhancing photocatalytic performance. By offering a comprehensive overview, we hope to highlight the potential of 3D graphene as an environmentally beneficial material and to inspire the development of more efficient, versatile graphene-based aerogel photocatalysts for future applications.

Keywords: aerogel; application; graphene; photocatalyst.

Figure 1

Scheme diagram of the photocatalytic process.

Figure 2

Systematic diagram of graphene and graphene-based derivatives. Reproduced with permission from Ref. [61], Copyright 2022, Elsevier.

Figure 3

Various roles of 3D graphene in the photocatalytic system.

Figure 4

3D graphene with different structures. (A) Fabrication process (i) and morphology (ii–v) of graphene aerogel spheres. Reproduced with permission from Ref. [84], Copyright 2020, Elsevier; (B) Fabrication (i) and structural characteristics (ii–v) of graphene foam. Reproduced with permission from Ref. [85], Copyright 2023, Elsevier; (C) Schematic illustration for the preparation of graphene aerogel. Reproduced with permission from Ref. [86], Copyright 2024, Elsevier; (D) Digital camera images (i,ii) and cross-sectional view SEM images (iii,iv) of graphene aerogel film. Reproduced with permission from Ref. [87], Copyright 2018, Elsevier; (E) Cross polarized-light optical images (i), SEM images (ii,iii), and photographs (iv,v) of graphene aerogel hollow fiber. Reproduced with permission from Ref. [88], Copyright 2022, Elsevier.

Figure 5

(A) Schematic diagram of the preparation process of 3D graphene by CVD (i–iv); (B) SEM images of copper template (i), graphene grown on copper template (ii), and graphene network after evaporating copper template (iii,iv). Reproduced with permission form Ref. [91], Copyright 2017, American Chemical Society.

Figure 6

(A) Schematic of a ceramic tube (i) and SEM image of polystyrene microspheres wrapped with graphene oxide (ii); (B) Fabrication process of graphene MOP film; (C) Morphologies of graphene-oxide composite films: SEM images of graphene-SnO₂ film (i,ii), TEM images of graphene-SnO₂ film (iii,iv), and SEM images of graphene-Fe₂O₃ (v) and graphene-NiO (vi). Reproduced with permission from Ref. [94], Copyright 2016, American Chemical Society.

Figure 7

(A) The procedure of preparing graphene aerogels by a combination of hydrothermal treatment (different time), lyophilization and hydrazine reduction: 20 min (i), 30 min (ii), and 40 min (iii); (B) The cross-sectional SEM images of graphene aerogels with different hydrothermal times and their corresponding magnified views: 20 min (i–iii), 30 min (iv–vi), 40 min (vii–ix). Reproduced with permission from Ref. [97], Copyright 2024, Elsevier.

Figure 8

(A) Fabrication procedure of the phase change materials with radial scaffold; (B) Morphology of the aerogel and phase change material: schematic diagram for cross-sectional SEM observation (i) and cross-section SEM (ii,iii) of graphene/chitosan aerogel, schematic diagram for longitudinal section SEM observation (iv) and longitudinal section SEM (v,vi) of graphene/chitosan aerogel, digital image (vii) and SEM images of graphene/chitosan-PCM (viii,ix). Reproduced with permission from Ref. [98], Copyright 2024, Elsevier.

Figure 9

(A) Schematic illustration of the emulsion soft-template synthesis procedures for preparing porous graphene foams; (B) SEM images (i,ii) and TEM images (iii–vi) of graphene using TMB as emulsion templates; (C) SEM images (i,ii) and TEM images (iii–vi) of graphene using n-hexadecane as emulsion templates. Reproduced with permission from Ref. [101], Copyright 2014, Royal Society of Chemistry.

Figure 10

(A) The formation mechanism for graphene hydrogel; (B) Photographs of graphene oxide solution before and after hydrothermal reduction; (C) SEM image of the interior microstructures of graphene. Reproduced with permission from Ref. [104], Copyright 2010, American Chemical Society.

Figure 11

Schematic illustration of 3D printing (A–C); SEM images (D–F), ultralight structure (G), and mechanical properties (H,I) of graphene. Reproduced with permission from Ref. [132], Copyright 2019, Wiley.

Figure 12

(A) Preparation schematic diagram of ZnO/graphene foam, inset is the corresponding sample photographs of each step; (B) SEM images of graphene/Ni (i), graphene (ii), and ZnO/graphene (iii–vi). Reproduced with permission from Ref. [142], Copyright 2016, Elsevier.

Figure 13

(A) Schematic illustration of the synthetic process of Bi₂WO₆/graphene; (B) SEM images of Bi₂WO₆ (i) and Bi₂WO₆/graphene (ii); (C) Schematic diagram of pollutants adsorption and photocatalytic degradation by Bi₂WO₆/graphene composite. Reproduced with permission from Ref. [178], Copyright 2017, Elsevier.

Figure 14

(A) SEM images of MoS₂/graphene with different synthetic process: hydrothermal method (i) and chemical activation route (ii); (B) Schematic of the photocatalysis mechanism under visible−light irradiation; (C) Probable pathways for photocatalytic degradation of tetracycline. Reproduced with permission from Ref. [110], Copyright 2024, American Chemical Society.

Figure 15

(A) A SEM image of 3D graphene (i), TEM images of TiO₂/graphene (ii,iv), and the lattice diffraction pattern of the particle in the white circle in (iii); (B) Electron transfer pathways in the photocatalytic hydrogen production by TiO₂/graphene. Reproduced with permission from Ref. [66], Copyright 2017, Springer.

Figure 16

(A) Fabrication process of (MoS₂ and WS₂) nanosheets/3D graphene; (B) SEM images of 3D graphene (i), MoS₂/graphene (ii), and WS₂/graphene (iii); (C) Schematic illustration of the transfer process in the photocatalyst system (i) and the photocatalytic performance comparison of this work with other photocatalysts in the literature (ii). Reproduced with permission from Ref. [187], Copyright 2024, American Chemical Society.

Figure 17

(A) Schematic illustration for the formation process of ZnIn₂S₄/N-graphene; (B) SEM images of N-graphene (i) and ZnIn₂S₄/N-graphene (ii); (C) Photogenerated charge transfer mechanism: valence band spectra (i), flat-band potentials (ii), and energy level diagram (iii). Reproduced with permission from Ref. [197], Copyright 2020, Springer.