Fast Interlayer Charge Separation and Transmission in ZnIn₂S₄/CNTs/ZnS Heterojunctions for Efficient Photocatalytic Hydrogen Evolution

Abstract

The construction of close contact heterojunction structures is crucial to modify photocatalytic performance. Here a series of heterojunction ZnIn 2 S 4 /CNTs/ZnS nanocomposites for photocatalytic hydrogen evolution were synthesized by a simple thermal reflux approach. The ideal ZnIn 2 S 4 /CNTs/ZnS sample has a photocatalytic hydrogen evolution rate of 0.9363 mmol • g À 1 • h À 1 with favorable cycle stability, which is about 16.9 and 5.5 times that of pure ZnIn 2 S 4 and binary ZnIn 2 S 4 /ZnS. The tight interfacial contact between ZnIn 2 S 4 , ZnS, and CNTs raises photogenerated charge carrier separation efficiency. CNTs have a high electrical conductivity, which allows them to receive and transport photogenerated electrons effectively. Therefore, the recombination of photon-generated charges may be efficaciously restrained, and the accepted electrons can be rapidly transported to reactive sites for production of hydrogen. Simultaneously, density functional theory (DFT) simulations show that introducing CNTs can enhance electronic characteristics and add additional charge carriers. This study shows that well-designed CNTs-based heterojunction structure can effectively promote charge separation in photocatalysis.

Multication and Structure Regulation: Utilizing X‐Doped (X = Co, Mn, Cu) ZnS/CoO Hollow Composites to Spatially Propel the Charge for Superior Solar Hydrogen Evolution

“…[ 35 ] The H 2 evolution efficiency of Co‐ZnS/CoO composite is also comparable to or exceeds the modified ZnS and CoO materials in recent works, even involving Pt‐deposited photocatalysts (Figure S23, Supporting Information). [ 14,33,41–48 ] Moreover, a “volcanic‐type” change is observed in the H 2 evolution rates of Co‐ZnS/CoO‐0.5, Co‐ZnS/CoO, and Co‐ZnS/CoO‐2, which indicates the sensitivity of CoO loading. The optimal Co‐ZnS/CoO photocatalyst has a high apparent quantum efficiency (AQE) value of 6.05% under the monochromatic light irradiation ( λ = 420 nm) in cocatalyst‐free condition, suggesting the greatly improved visible‐light‐driven H 2 generation efficiency in hollow star‐shaped heterostructure.…”

Development of Z-scheme bimetallic tungstate-supported nitrogen deficient g-C3N4heterojunction for the treatment of refractory pharmaceutical pollutants

“…Furthermore, all the analyzed samples have a positive slope on the M–S graphs, indicating n-type semiconductor characteristics. The following formula was used to determine the conduction band minimum (CBM): 52 E fb (NHE) = E fb(Ag/AgCl) + E (Ag/AgCl) + 0.059 pH,where the sodium sulphate electrolyte has a pH of 7 and the E (AgCl) = 0.197 V at 25 °C. Consequently, the E CBM of ND-GCN, NCW, and CZW were claimed to be −1.16 V, 0.29 V, and 0.39 V vs. NHE, respectively.…”

Tailoring Charge Separation in ZnIn2S4@CdS Hollow Nanocages for Simultaneous Alcohol Oxidation and CO2 Reduction under Visible Light

“…According to previous studies, low dimensional metal sulfides such as ZnIn 2 S 4 , Zn 3 In 2 S 6 , CdS, and CdIn 2 S 4 are promising photocatalysts due to their wide visible light absorption, suitable energy band structure, unique photoelectric characteristic, manageable growth, and simple preparation. − More importantly, under visible light irradiation, they can photocatalytically reduce CO 2 , and the CO 2 reduction activity could be enhanced by coupling with other photocatalysts. , Additionally, they also exhibited efficiently photocatalytic activity for selective oxidation of alcohols into corresponding aldehydes in the presence of O 2 . Therefore, metal sulfides may be potential candidates for simultaneous CO 2 reduction and aromatic alcohol oxidation in one reaction system by a rational design.…”