In Situ Construction of a Cs₂SnI₆ Perovskite Nanocrystal/SnS₂ Nanosheet Heterojunction with Boosted Interfacial Charge Transfer

Abstract

Heterojunction engineering has played an indispensable role in the exploitation of innovative artificial materials with exceptional properties and has consequently triggered a new revolution in achieving high-performance optoelectronic devices. Herein, an intriguing halide perovskite (PVK) and metal dichalcogenide (MD) heterojunction, i.e., a lead-free Cs2SnI6 perovskite nanocrystal/SnS2 nanosheet hybrid, was fabricated in situ for the first time. Comprehensive investigations with experimental characterizations and theoretical calculations demonstrate that cosharing of the Sn atom enables intimate contact in the Cs2SnI6/SnS2 hybrid together with a type II band alignment structure. Additionally, ultrafast carrier separation between SnS2 and Cs2SnI6 has been observed in the Cs2SnI6/SnS2 hybrid by transient absorption measurements, which efficiently prolongs the lifetime of the photogenerated electrons in SnS2 (from 1290 to 3080 ps). The resultant spatial charge separation in the Cs2SnI6/SnS2 hybrid evidenced by Kelvin probe force microscopy (KPFM) significantly boosts the photocatalytic activity toward CO2 reduction and the photoelectrochemical performance, with 5.4-fold and 10.6-fold enhancements compared with unadorned SnS2. This work provides a facile and effective method for the in situ preparation of PVK-MD heterojunctions, which may significantly stimulate the synthesis of various perovskite-based hybrid materials and their further optoelectronic applications.

Hierarchical Porous Molybdenum Carbide Based Nanomaterials for Electrocatalytic Hydrogen Production

“…Yuan et al (2019) used the precursor spheres formed by F127 and resoled phenolic resin to limit the growth of molybdenum carbide, and obtained ultra-small Mo 2 C particles encapsulated in situ in mesoporous carbon spheres (Mo 2 C@MCS). The ultrasmall particle size exposes more active sites, and the presence of a carbon substrate greatly reduces the resistance of the catalyst, thereby exhibiting excellent electrocatalytic performance in an alkaline medium (Liu et al, 2018;Huang et al, 2019d). This study provides an effective strategy for the synthesis of a Mo x C@C catalyst.…”

“…Heterostructured hybrids have shown superior electrochemical performance compared to the corresponding single components (Liang et al, 2019;Yao et al, 2019). Through the interface electron transfer in a heterostructure, a large number of interfaces between multiple components can induce optimization of the electronic configuration (Wang et al, 2019d;He et al, 2020). Therefore, constructing heterojunction is an effective way to optimize the free energy of hydrogen adsorption.…”

Recent Progress in Engineering Metal Halide Perovskites for Efficient Visible‐Light‐Driven Photocatalysis

“…This work presents a significant step towards implementing this unique composite in artificial photocatalysis. In 2019, the group of Kuang prepared a lead‐free Cs 2 SnI 6 /SnS 2 heterojunction through a facile in situ solution method (Figure a) . The Cs 2 SnI 6 /SnS 2 heterojunction, with a type II band alignment structure, possesses an intimate contact interface due to the cosharing of Sn atoms (Figure b).…”

Investigation of Water‐Stable Perovskite DMASnIxBr3−x for Photoenzyme Catalysis in Aqueous Solution

“…[19,20] Recently, perovskite materials indeed exhibited promising applications in conventional photocatalysis, such as hydrogen evolution, CO 2 reduction, dye degradation, as well as organic synthesis. [21][22][23][24][25][26][27][28][29][30][31][32][33][34] However, the perovskitebased photocatalytic processes were usually conducted in the oversaturated hydroiodic acid solution or alcohol-based systems. [21,22,25,31] The extreme sensitivity to water could easily render the perovskite materials such as MAPbI 3 degrade into PbI 2 .…”