Recent advances in g-C3N4-based photocatalysts incorporated by MXenes and their derivatives
23 Jun 2021-Journal of Materials Chemistry (The Royal Society of Chemistry)-Vol. 9, Iss: 24, pp 13722-13745
TL;DR: In this article, a discussion of the fundamental photocatalytic mechanism over graphitic carbon nitride (g-C3N4)-based photocatalyst with MXenes and MXene derivatives is presented.
Abstract: As one of the fascinating visible-light-responsive photocatalysts, the two-dimensional (2D) graphitic carbon nitride (g-C3N4) has drawn broad attention in the field of solar energy conversion and environmental remediation. However, intrinsic drawbacks, such as insufficient surface area, slow electron transfer and unsatisfied visible-light absorption hinder its promising applications. The incorporation of 2D MXenes and their derivatives into g-C3N4 is recognized as an effective approach to totally enhance their performance toward advanced photocatalysts. This work starts with a discussion of the fundamental photocatalytic mechanism over g-C3N4-based photocatalysts incorporated with MXenes and MXene derivatives. Then, we give a comprehensive overview on the main strategies for constructing such hybrid photocatalysts with a solid 2D/2D interfacial contact. Afterward, their typical applications in environmental and energy fields, including H2 generation, CO2 conversion, pollutant degradation, N2 fixation and H2O2 production, are discussed systematically. Finally, some concluding remarks and perspectives in this area are proposed.
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TL;DR: In this article, the authors determined that nitrogen vacancies (NVs) could endow graphitic carbon nitride (g-C₃N₄) with the photocatalytic N₂ fixation ability.
Abstract: Photoreduction of N₂ is among the most interesting and challenging methods for N₂ fixation under mild conditions. In this study, we determined that nitrogen vacancies (NVs) could endow graphitic carbon nitride (g-C₃N₄) with the photocatalytic N₂ fixation ability. Photocatalytic N₂ fixation induced by NVs is free from the interference of other gases. The reason is that NVs could selectively adsorb and activate N₂ because NVs have the same shape and size as the nitrogen atom in N₂. In addition to this, NVs could also improve many other properties of g-C₃N₄ to support photocatalytic N₂ fixation. These new findings could elucidate the design of efficient photocatalysts for photocatalytic N₂ fixation.
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References
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TL;DR: It is anticipated that this review can stimulate a new research doorway to facilitate the next generation of g-C3N4-based photocatalysts with ameliorated performances by harnessing the outstanding structural, electronic, and optical properties for the development of a sustainable future without environmental detriment.
Abstract: As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and “earth-abundant” nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The constructi...
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