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The 3DOM TiO 2 -Au-CdS inverse opal photonic crystal structure is designed for visible-light hydrogen production, exhibiting extremely enhanced photocatalytic activity via coupling bifunctional SPR effect and electron transfer of Au NPs with slow photon effect. [Display omitted] • The ternary TiO 2 -Au-CdS (TAC) photocatalysts have been designed to couple the bifunctional Au NPs with slow photon effect. • A two electron transfer paths model is proposed in the ternary TAC photocatalysts. • Finite-difference time-domain (FDTD) simulations are used to reveal the size effect of Au NPs. • The ternary TAC-10 photocatalyst with ~ 10 nm Au NPs demonstrates the highest hydrogen evolution rate under visible-light. Gold nanoparticles (Au NPs) with surface plasmonic resonance (SPR) effect and excellent internal electron transfer ability have widely been combined with semiconductors for photocatalysis. However, the in-depth effects of Au NPs in multicomponent photocatalysts have not been completely understood. Herein, ternary titanium oxide-gold-cadmium sulfide (TiO 2 -Au-CdS, TAC) photocatalysts, based on hierarchical TiO 2 inverse opal photonic crystal structure with different Au NPs sizes have been designed to reveal the SPR effect and internal electron transfer of Au NPs in the presence of slow photon effect. It appears that the SPR effect and internal electron transfer ability of Au NPs, depending on their sizes, play a synergistic effect on the photocatalytic enhancement. The ternary TAC-10 photocatalyst with ~ 10 nm Au NPs demonstrates an unprecedented hydrogen evolution rate of 47.6 mmolh-1g−1 under visible-light, demonstrating ~ 48% enhancement comparing to the sample without slow photon effect. In particular, a 9.83% apparent quantum yield under 450 nm monochromatic light is achieved for TAC-10. A model is proposed and finite-difference time-domain (FDTD) simulations reveal the size influence of Au NPs in ternary TAC photocatalysts. This work suggests that the rational design of bifunctional Au NPs coupling with slow photon effect could largely promote hydrogen production from visible-light driven water splitting. [ABSTRACT FROM AUTHOR]

• n -p heterojunction of TiO 2 -NiO ultrafine core-shell nanoparticles are prepared. • Strong interfacial interaction significantly improve charge separation efficiency. • As-fabricated photocatalyst exhibits excellent H 2 production from water splitting. • H 2 , CH 4 and fatty acids are cogenerated from biomass lignin photoreforming. Hydrogen evolution from biomass photoreforming has been widely recognized as a promising strategy for relieving the pressure from energy crisis and environmental pollution, as it could generate sustainable H 2 and value-added bioproducts simultaneously. Combining p-type semiconductors with n -type semiconductors to form n -p heterojunction is an effective strategy to improve the photocatalytic quantum efficiency by enhancing the separation of photogenerated electrons and holes, which could greatly facilitate the realization of such biomass photorefinery concept. However, the incompact contact between the n -type and p-type semiconductors often induces the aggregation of photogenerated electrons and holes. In this work, we design and synthesize an ultrafine n -p heterojunction TiO 2 -NiO core-shell structure to overcome the incompact contact in the n -p interface. When the n -p heterojunction photocatalysts are evaluated for photocatalytic water splitting and biomass lignin photoreforming respectively, the as-fabricated TiO 2 -NiO nanocomposite with 3.25% NiO demonstrates the highest hydrogen generation of 23.5 mmol h−1 g−1 from water splitting and H 2 (0.45 mmol h−1 g−1) and CH 4 (0.03 mmol h−1 g−1) cogeneration with reasonable amount of fatty acids (palmitic acid and stearic acid) production from lignin photoreforming. The excellent photocatalytic activity is ascribed to the synergistic effects of high crystallinity of TiO 2 ultrafine nanoparticles, core-shell structure and n -p heterojunction with NiO nanoclusters. This present work demonstrates a simple and efficient method to fabricate ultrafine n -p heterojunction core-shell structure for noble-metal free catalyst for both water splitting and biomass photoreforming. [ABSTRACT FROM AUTHOR]

[Display omitted] Photorefining of biomass is increasingly recognized as a pivotal technology for the simultaneous production of hydrogen and value-added chemicals. The intrinsic recalcitrance of lignocellulosic biomass puts high demands on the rational design of bifunctional photocatalyst. Herein, Ni 2 P/CdS with a strong interfacial effect in this work was designed to overcome lignocellulosic biomass photorefining. The strong interfacial effect between Ni 2 P and CdS not only improved the light absorbance, but also optimized the spatial redistribution of photogenerated electrons and holes. Therefore, Ni 2 P/CdS exhibited an unprecedented H 2 evolution activity (ca. 199.7 mmol·h−1·g−1) in the presence of lactic acid as the traditional sacrificial agent. Considerable H 2 generation was also achieved in the presence of lignin (ca. 322.8 μmol·h−1·g−1), cellulose (ca. 534.3 μmol·h−1·g−1) and hemicellulose (ca. 382.2 μmol·h−1·g−1) as the electron donor respectively. Theoretical calculation results indicated that establishing the interfacial effect between Ni 2 P and CdS optimized their work functions. This optimization fosters improved the redistribution between electrons and holes, as a result, photocatalytic hydrogen production from biomass solution was greatly enhanced. Significantly, Ni 2 P/CdS showed dual functionalities to produce H 2 and value-added compounds from raw biomass directly. This present work demonstrates the potential of raw biomass photorefining through astutely designing photocatalysts. [ABSTRACT FROM AUTHOR]

We report three types of conducting polymers (CPs), polyaniline (PANI), polypyrrole (PPY) and poly (3,4-ethylenedioxythiophene) (PEDOT) to modify the surface of the CdS nanorods to probe their photocorrosion inhibition and photocatalytic hydrogen production. Various characterizations, such as high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and density function theory (DFT) calculations have been conducted to reveal the intrinsic structure of the as-constructed CPs@CdS (@ means CPs at the surface of CdS) core-shell nanorods. The results show that the PANI and PPY shells with abundant N and C atoms can significantly enhance the binding energy of Cd and S atoms on the surface of the CdS nanorods. However, there is no obvious enhancement of binding energy at the interface of the PEDOT shell and the CdS nanorods core. Therefore, PANI@CdS and PPY@CdS possess stronger driving force than PEDOT@CdS to inject the photogenerated holes in conducting polymer shells. As a result, the polyaniline (PANI) modified PANI@CdS core-shell nanorods demonstrate the most effectively enhanced hydrogen production rate of ∼9.7 mmol h −1  g −1 and effective photocorrosion inhibition in 30 h without deactivation under visible-light irradiation. The hydrogen production performance of PPY@CdS is not effectively promoted owing to the weak transmittance of light for the PPY shell. The PEDOT shell cannot improve the hydrogen production and stability property of the CdS nanorods. This work could shed some light on conducting polymers modifying metal sulfides nanostructures that is of inconceivable significance for effective photocorrosion inhibition and highly enhanced photocatalytic activities. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Ni clusters accelerate the separation and transmission of the photogenerated electrons and holes. • The in-situ photoluminescence measurement confirms the Ni clusters as more active sites for hydrogen production. • The Ni/ZnIn 2 S 4 composites demonstrate remarkable hydrogen production rate. • The Ni/ZnIn 2 S 4 composites exhibit good stability and reusability. As a typical two-dimensional (2D) metal chalcogenides and visible-light responsive semiconductor, zinc indium sulfide (ZnIn 2 S 4) has attracted much attention in photocatalysis. However, the high recombination rate of photogenerated electrons and holes seriously limits its performance for hydrogen production. In this work, we report in-situ photodeposition of Ni clusters in hierarchical ZnIn 2 S 4 nanoflowers (Ni/ZnIn 2 S 4) to achieve unprecedented photocatalytic hydrogen production. The Ni clusters not only provide plenty of active sites for reactions as evidenced by in-situ photoluminescence measurement, but also effectively accelerate the separation and migration of the photogenerated electrons and holes in ZnIn 2 S 4. Consequently, the Ni/ZnIn 2 S 4 composites exhibit good stability and reusability with highly enhanced visible-light hydrogen production. In particular, the best Ni/ZnIn 2 S 4 photocatalyst exhibits an unprecedented hydrogen production rate of 22.2 mmol·h−1·g−1, 10.6 times that of the pure ZnIn 2 S 4 (2.1 mmol·h−1·g−1). And its apparent quantum yield (AQY) is as high as 56.14% under 450 nm monochromatic light. Our work here suggests that depositing non-precious Ni clusters in ZnIn 2 S 4 is quite promising for the potential practical photocatalysis in solar energy conversion. [ABSTRACT FROM AUTHOR]

MoS 2 quantum dots (QDs) in-situ directing porous MoS 2 -QDs/ZnIn 2 S 4 heterostructures exhibit the H 2 production rate under visible light. Photocatalytic hydrogen (H 2) production based on semiconductors is important to utilize solar light for clean energy and environment. Herein, we report a visible light responsive heterostructure, designed and constructed by molybdenum disulfide quantum dots (MoS 2 -QDs) in-situ seeds-directing growth and self-assemble of zinc indium sulfide (ZnIn 2 S 4) nanosheet to ensure their full contact through a simple one-step solvothermal method for highly improved visible light H 2 production. The MoS 2 -QDs in-situ seeds-directing ZnIn 2 S 4 heterostructure not only builds heterojunctions between MoS 2 and ZnIn 2 S 4 to spatially separate the photogenerated electrons and holes, but also serves as the active sites trapping photogenerated electrons to facilitate H 2 evolution. As a result, MoS 2 -QDs/ZnIn 2 S 4 exhibits high photocatalytic activity for H 2 production, and the optimized 2 wt% MoS 2 -QDs/ZnIn 2 S 4 (2MoS 2 -QDs/ZnIn 2 S 4) heterostructure exhibits the highest H 2 evolution rate of 7152 umol·h−1·g−1 under visible light, ∼9 times of pure ZnIn 2 S 4. Our strategy here could shed some lights on developing noble-metal free heterostructures for highly efficient photocatalytic H 2 production. [ABSTRACT FROM AUTHOR]