Ultrathin Two‐Dimensional Semiconductors for Photocatalysis in Energy and Environment Applications

Abstract

The search for highly active photocatalysts remains one of the most challenging tasks for realizing efficient solar energy utilization. Inspired by their unique and excellent physicochemical properties, ultrathin two-dimensional (2D) semiconductors present great advantages in photocatalytic researches. In this review, we summarize the state-of-art progress on the ultrathin 2D semiconductors with a particular emphasis on their recent advances in energy and environment applications. First, we introduce the historical developments of 2D nanomaterials, and outline their advantages in terms of photocatalysis. Second, the classifications of ultrathin 2D semiconductors are summarized based on their structure and compositions. Further, various energy and environment applications including water splitting, CO 2 reduction, N 2 fixation, organic syntheses, NO x removal, water treatment, and sterilization in recent years (mainly in the recent 3 years) are highlighted in detail. Finally, the personal perspectives on future challenges and outlooks in the field of energy and environment applications are featured.[a] Dr.

Metal-Free Photocatalysis: Two-Dimensional Nanomaterial Connection toward Advanced Organic Synthesis

“… 10 In addition, thicknesses can be reduced to a few nanometers, or even, in some cases, to monatomic sizes, using modern synthetic approaches. 11 These geometric features are notably correlated with quantum and dielectric confinement effects, which modify the band structure and, consequently, the band gap. 12 Typically, the band gap widens due to quantum confinement, and upshifts of the conduction band (CB) are observed, enhancing both the potential energy of the photogenerated electrons and their reduction ability.…”

Nanoenabled Photothermal Materials for Clean Water Production

“…Solar absorbing material was deposited by TiO 2 while solar evaporation generates. It captures the solar spectrum in the range of UV radiation along with electron–hole generation for RhB [ 36,201 ] degradation, whereas photothermal material for photothermic transformation for performing the steam generation is absorbed by the visible and NIR light. [ 199,200 ] This method for photocatalysis is also coupled with physical adsorption to eliminate contaminants effectively.…”

“…Therefore, structures of photothermic materials should be further explored in the hypotheses of the removal of not only non‐solid organic pollutants but also VOCs through adsorption, photocatalysis [ 202,203 ] or photothermal‐assisted catalysis process for water purification. [ 36,201 ]…”

2D mesoporous ultrathin Cd0.5Zn0.5S nanosheet: Fabrication mechanism and application potential for photocatalytic H2 evolution

“…In par-ticular, ultrathin 2D structures with large specific surface areas can create abundant fast interfacial channels and large interfacial contacts between photocatalyst and reactant molecules. Furthermore, the predominant exposure of a specific facet endows it with a significant amount of low-coordinated surface atoms, facilitating the adsorption and activation of reactants on the unsaturated surface atoms [4][5][6]. The aforementioned attractive features make ultrathin 2D photocatalysts promising candidates for the development of highly efficient artificial photosynthesis systems.…”