Preparation of NiS/ZnIn2S4 as a superior photocatalyst for hydrogen evolution under visible light irradiation

Metal Chalcogenides Based Heterojunctions and Novel Nanostructures for Photocatalytic Hydrogen Evolution

The photo-conversion efficiency is a key issue in the development of new photocatalysts for solar light driven water splitting applications. In recent years, different engineering strategies have been proposed to improve the photogeneration and the lifetime of charge carriers in nanostructured photocatalysts. In particular, the rational design of heterojunctions composites to obtain peculiar physico-chemical properties has achieved more efficient charge carriers formation and separation in comparison to their individual component materials. In this review, the recent progress of sulfide-based heterojunctions and novel nanostructures such as core-shell structure, periodical structure, and hollow cylinders is summarized. Some new perspectives of opportunities and challenges in fabricating high-performance photocatalysts are also discussed.

Path of electron transfer created in S-doped NH2-UiO-66 bridged ZnIn2S4/MoS2 nanosheet heterostructure for boosting photocatalytic hydrogen evolution

This work introduces the synthesis of ZnIn₂S₄/NH₂-UiO-66/MoS₂ sheet heterostructure photocatalysts and their application to photocatalytic hydrogen evolution.

Recent advances in metal sulfides: from controlled fabrication to electrocatalytic, photocatalytic and photoelectrochemical water splitting and beyond

This review describes an in-depth overview and knowledge on the variety of synthetic strategies for forming metal sulfides and their potential use to achieve effective hydrogen generation and beyond.

Nickel sulfide/graphitic carbon nitride/strontium titanate (NiS/g-C3N4/SrTiO3) composites with significantly enhanced photocatalytic hydrogen production activity

NiS/g-C₃N₄/SrTiO₃ (NS/CN/STO) composites were prepared using a facile hydrothermal method. The synergistic effect of g-C₃N₄/SrTiO₃ (CN/STO) heterojunction and NiS cocatalyst enhanced the photocatalytic hydrogen evolution activity of NS/CN/STO. A hydrogen production rate of 1722.7 μmol h^-1 g^-1 was obtained when the 2%NiS/20%g-C₃N₄/SrTiO₃ (2NS/20CN/STO) was used for the photocatalytic hydrogen evolution in the presence of methanol used as a sacrificial agent under UV-vis light irradiation; the photocatalytic hydrogen production rate of 2NS/20CN/STO is 32.8, 8.9 and 4.2 times the value of that obtained with pure g-C₃N₄, SrTiO₃ and 20%g-C₃N₄/SrTiO₃ (20CN/STO), respectively. Moreover, in photoelectrochemical investigations when compared with 20CN/STO, SrTiO₃ and g-C₃N₄, 2NS/20CN/STO exhibited significant photocurrent enhancement. The heterojunction and cocatalyst in NS/CN/STO improved the charge separation efficiency and the lifetime of the charge carriers, leading to the enhanced generation of electrons for photocatalytic hydrogen production.

Synthesis of layer-like Ni(OH)2 decorated ZnIn2S4 sub-microspheres with enhanced visible-light photocatalytic hydrogen production activity

Novel layer-like Ni(OH)₂ co-catalyst-decorated ZnIn₂S₄ microsphere photocatalysts were synthesized for the first time via a facile in situ deposition method to boost the photocatalytic H₂-production performance.

Wide spectrum responsive CdS/NiTiO3/CoS with superior photocatalytic performance for hydrogen evolution

Wide spectrum responsive CdS/NiTiO₃/CoS with superior photocatalytic performance for H₂ evolution.

Co(dmgH)2pyCl as a noble-metal-free co-catalyst for highly efficient photocatalytic hydrogen evolution over hexagonal ZnIn2S4

Co(dmgH)₂pyCl is an efficient co-catalyst for photocatalytic hydrogen evolution and the activity over Co(dmgH)₂pyCl/ZnIn₂S₄ is superior to that over Pt/ZnIn₂S₄.

ZnO/ZnS heterostructures for hydrogen production by photoelectrochemical water splitting

ZnO/ZnS heterostructures anodized under stirring conditions and in glycerol/water electrolyte succeeded as being a photococatalyst for photoelectrochemical water splitting.

Hierarchical core-shell carbon nanofiber@ZnIn₂S₄ composites for enhanced hydrogen evolution performance

Improvement of hydrogen evolution ability is an urgent task for developing advanced catalysts. As one of the promising visible-light photocatalysts, ZnIn2S4 suffers from the ultrafast recombination of photoinduced charges, which limits its practical application for efficient solar water splitting. Herein, we reported a two-step method to prepare hierarchical core-shell carbon nanofiber@ZnIn2S4 composites. One-dimensional carbon nanofibers were first prepared by electrospinning and carbonization in N2. The subsequent solvothermal process led to the in situ growth of ZnIn2S4 nanosheets on the carbon nanofibers to fabricate hierarchical structure composites. The hierarchical core-shell configuration structure can help to form an intimate contact between the ZnIn2S4 nanosheet shell and the carbon nanofiber backbone compared with the equivalent physical mixture and can facilitate the interfacial charge transfer driven by the excitation of ZnIn2S4 under visible-light irradiation. Meanwhile, the ultrathin ZnIn2S4 nanosheets were uniformly grown on the surface of the carbon nanofibers, which can avoid agglomeration of ZnIn2S4. These synergistic effects made this unique hierarchical structure composite exhibit a significantly higher visible-light photocatalytic activity toward hydrogen evolution reaction compared with pure ZnIn2S4 or a physical mixture of ZnIn2S4 and carbon nanofibers in the absence of noble metal cocatalysts.

Enhancement of photocatalytic H2 evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

A graphene oxide (GO) solution was irradiated by a Xenon lamp to form reduced graphene oxide (RGO). After irradiation, the epoxy, the carbonyl and the hydroxy groups are gradually removed from GO, resulting in an increase of sp(2) π-conjugated domains and defect carbons with holes for the formed RGO. The RGO conductivity increases due to the restoration of sp(2) π-conjugated domains. The photocatalytic activity of EY-RGO/Pt for hydrogen evolution was investigated with eosin Y (EY) as a sensitizer of the RGO and Pt as a co-catalyst. When the irradiation time is increased from 0 to 24 h the activity rises, and then reaches a plateau. Under optimum conditions (pH 10.0, 5.0 × 10(-4) mol L(-1) EY, 10 μg mL(-1) RGO), the maximal apparent quantum yield (AQY) of EY-RGO24/Pt for hydrogen evolution rises up to 12.9% under visible light irradiation (λ ≥ 420 nm), and 23.4% under monochromatic light irradiation at 520 nm. Fluorescence spectra and transient absorption decay spectra of the EY-sensitized RGO confirm that the electron transfer ability of RGO increases with increasing irradiation time. The adsorption quantity of EY on the surface of RGO enhances, too. The two factors ultimately result in an enhancement of the photocatalytic hydrogen evolution over EY-RGO/Pt with increasing irradiation time. A possible mechanism is discussed.