Enhanced Photocatalytic Property of γ-CsPbI₃ Perovskite Nanocrystals with WS₂

Abstract

Black perovskite-phase cesium lead tri-iodide (CsPbI 3 ) has shown great potential in photochemical applications. However, colloidal CsPbI 3 still suffers from the existence of ligands attached to the surface of nanocrystals (NCs) and serious photoluminescence (PL) quenching. Here, we develop two different γ-phase CsPbI 3 (γ-CsPbI 3 ) NCs/ WS 2 heterostructures with two different two-dimensional morphologies of WS 2 (nanoplates and few-layered WS 2 nanosheets) to improve the photocatalytic property of γ-CsPbI 3 NCs. The large surface area and the presence of abundant functional groups on the surface of WS 2 enable a bonding interaction with precursors in the mixture solution, which can reduce the number of ligands and promote the formation and crystal quality of γ-CsPbI 3 NCs. Exhilaratingly, we find that γ-CsPbI 3 NCs fabricated with few-layered WS 2 nanosheets exhibit a significant enhancement in their photocatalytic property, which may result from the increased amount and improved crystal quality of γ-CsPbI 3 NCs and the superior carrier-transport property of few-layered WS 2 nanosheets, and these effects are beneficial for producing abundant hydroxyl radicals to completely degrade methylene blue (MB). The fresh γ-CsPbI 3 NCs/few-layered WS 2 nanosheets show a high photocatalytic degradation efficiency of nearly 100% in 30 min, and completely degrade MB into low-weight and low-toxicity inorganic molecules without any intermediate degradation products.

Lead-free CsSnCl3 perovskite nanocrystals: rapid synthesis, experimental characterization and DFT simulations

“…4 (b), two distinct peaks can be observed at the binding energies of 723.9 eV and 737.8 eV in the Cs 3d XPS spectrum which can be ascribed to the presence of Cs 3d 5/2 and Cs 3d 3/2 states, respectively. [58] As shown in Fig. 4 (c), the core level spectrum of Sn was distinguished by the two pronounced peaks at 485.6 eV and 494 eV corresponding to the states of Sn 3d 5/2 and Sn 3d 3/2 , respectively.…”

Recent Progress on Carbon Nitride and Its Hybrid Photocatalysts for CO2 Reduction

“…Lead halide perovskite materials, as one of the hottest star materials for photovoltaics and optoelectronic applications, have also shown their potential for photocatalytic applications. [ 123–127 ] Ou et al combined CsPbBr 3 quantum dots with NH x ‐rich porous g‐C 3 N 4 nanosheets via NBr chemical bonding to form a type I heterojunction photocatalyst. [ 128 ] The strong NBr bonds lead to close bonding of the two materials.…”

Perovskite Nanocrystals‐Based Heterostructures: Synthesis Strategies, Interfacial Effects, and Photocatalytic Applications

“…Similiarly, Zhao and co‐workers also regulate the light‐absorption range of WS 2 through the γ–CsPbI 3 PNCs modification (Figure 7a). [ 95 ] In view of this, PNCs are commonly used to improve light absorption on various other materials, and the continuously tunable bandgap properties of PNCs can precisely regulate the optical absorption range of the corresponding composite materials through the effective heterostructure interface, which is of considerable significance to the development of the photocatalytic field.…”

“…a) UV–vis diffused absorption spectra of γ‐CsPbI 3 PNCs/WS 2 ; Reproduced with permission. [ 95 ] Copyright 2020, Journal of the American Chemical Society. b) UV–vis diffused absorption spectra of Ag‐CsPbBr 3 QDs/C 3 N 4 ; Reproduced with permission.…”

“…For example, a novel γ‐CsPbI 3 PNCs/few‐layered WS 2 heterostructure was constructed, showing a photocatalytic efficiency of nearly 100% in methylene blue (MB) degradation. [ 95 ] The improved photocatalytic property was benefited from the superior carrier‐transport property of few‐layered WS 2 nanosheets, which produced abundant hydroxyl radicals to degrade MB. Also, similar to the design idea of CO 2 reduction photocatalyst, MOF and C 3 N 4 are often used to construct PNCs‐based heterostructure with PNCs increasing the stability of the composite and promoting the adsorption of organic pollutants.…”