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Developing a high-efficiency visible light photocatalyst is always a research hotspot in photocatalytic field. In this study, a novel Z-scheme photocatalyst WO 3 /g-C 3 N 4 with high efficient visible light photocatalytic activity was prepared via ball milling and heat treatment methods. The photocatalyst was characterized by X-ray powder diffraction (XRD), UV–vis diffuse reflection spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron spin resonance (ESR), and photoluminescence (PL). The photocatalytic activity was evaluated by degradation of methylene blue (MB) and fuchsin (BF) under visible light illumination. The results showed that composite WO 3 /g-C 3 N 4 exhibits a much higher photocatalytic activity than a single g-C 3 N 4 . The rate constants of photocatalytic degradation of MB and BF for WO 3 (5.0 wt.%)/g-C 3 N 4 are 4.77 times and 3.84 times that of pure g-C 3 N 4 . The characterization results by physical and chemical methods demonstrated that composite WO 3 /g-C 3 N 4 is a typical Z-scheme photocatalyst. The enhancement of the photocatalytic activity may be attributed to the formation of the Z-scheme system between g-C 3 N 4 and WO 3 , which could result in the photoexcited electrons of g-C 3 N 4 and photoexcited holes of WO 3 participating in oxidation and reduction reactions, respectively. [ABSTRACT FROM AUTHOR]

Highlights: [•] g-C3N4-WO3 photocatalysts with different main parts of C3N4 or WO3 were prepared. [•] The band–band transfer for g-C3N4/WO3 and the Z-scheme for WO3/g-C3N4 were proposed. [•] The activity of g-C3N4/WO3 is not obviously increased compared with pure WO3. [•] The activity of WO3/g-C3N4 is increased greatly compared with pure g-C3N4. [ABSTRACT FROM AUTHOR]

Interfacial charge transfer efficiency and electronic states of active sites are two essential issues to restrict catalytic activity of electrocatalysts for oxygen evolution reaction (OER). In this work, we show that although Au is recognized to be inert towards OER, the catalytic activity of Fe 3 O 4 catalyst for OER was highly boosted by coupling Fe 3 O 4 with Au to address these two issues. Here, Au nanoparticles were attached to hierarchical Fe 3 O 4 microsphere through electrochemical deposition, a mild and rapid approach that can be accomplished within 3 min and requires no sophisticated equipment. With the coupling of Au, interfacial charge transfer resistance of Fe 3 O 4 declined remarkably. On the other hand, oxidability of Fe sites and electron accepting capability of Au sites was elevated due to strong interaction between Au and Fe 3 O 4. Owing to these two merits induced by Au, Fe 3 O 4 exhibited enhanced catalytic activity for OER. The potential of Fe 3 O 4 to obtain 10 mA/cm2 decreased by 640 mV, the current density was amplified up to 2.5 fold at the potential of 2 V (vs SCE), and the Tafel slop was reduced by 146 mV/dec. This work shows that the catalytic activity of an earth-abundant electrocatalyst (Fe 3 O 4) for OER reaction was boosted by coupling it with OER-inert Au. It is found that the coupling of Au not only facilitated charge transfer efficiency of the catalyst, but elevated the oxidability of Fe sites and electron accepting capability of Au sites. Thereby, when coupled with Au, Fe 3 O 4 exhibited enhanced current density, reduced overpotential, and smaller Tafel slop. [Display omitted] • Enhance catalytic activity of Fe 3 O 4 for OER reaction via coupling of OER-inert Au. • Effectively promoted interfacial charge transfer with the decoration of Au. • Modify the state of Fe sites and Au sites by strong interaction of Au with Fe 3 O 4. • An easy-to-handle and rapid way to couple Au with hierarchical Fe 3 O 4 microspheres. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is considered as a promising approach to storing renewable electricity in the form of hydrogen fuel. In this work, we report the design and electrocatalytic properties of chiral CuO@Ni with three dimensional (3D) continuous macroporous framework. With the chiral CuO@Ni as anode, the OER overpotential required to achieve the current density of 10 mA/cm2 was as low as 110 mV in 0.1 M KOH electrolyte, and the hydrogen production rate of water splitting reaction could reach 1070 nL/s. Moreover, the OER overpotential could be regulated easily by controlling the deposition time of chiral CuO layer on Ni. The high catalytic activity of chiral CuO@Ni for water splitting is closely associated with the Chiral-induced spin selectivity ( CISS ) effect, the large reactive area provided by its 3D macroporous structure, and the effective cooperation between chiral CuO and Ni foam that facilitated the transportation of spin aligned electrons from chiral CuO layer to Ni. The results shown in this work indicate a simple and promising strategy to improve the electrocatalytic activity of other chiral earth-abundant catalysts for water splitting. This work shows the design and properties of chiral CuO@Ni with three dimensional continuous macroporous framework. The chiral CuO@Ni exhibited lower OER overpotential and larger current density than many CuO-based catalysts. Its high catalytic activity for water splitting reaction is attributed to the CISS effect of chiral CuO, the large reactive area of its 3D porous structure, and the synergistic interaction between the chiral CuO and the Ni foam. Image 1 • Chiral CuO@Ni with three dimensional continuous macroporous framework. • Low OER overpotential (110 mV) to achieve 10 mA/cm2 current density. • Easy and effective way to enhance the activity of chiral earth-abundant catalyst. [ABSTRACT FROM AUTHOR]

Interfacial charge separation is an essential issue to restrict catalytic activity of photocatalysts. In this work, we report a promising and easy-to-handle strategy to modulate the activity of a C 60 -based photocatalyst (C 60 @Pt) for visible-light-driven hydrogen evolution reaction (HER) with the coupling of magnetic substance that had weak ferromagnetism (Fe 3 O 4 microbeads as an instance). It is found that Fe 3 O 4 microbeads played a pivotal role in boosting photocatalytic activity and apparent quantum efficiency of C 60 @Pt for visible-light-driven HER, as the weak local magnetic field it induced around C 60 @Pt contributed to facilitating the separation of photo electrons from electron-donor in reaction system. This work shows a promising strategy to enhance photocatalytic activity of C 60 -based photocatalyst (C 60 @Pt as an instance) for visible-light-driven hydrogen evolution by coupling it with magnetic substance Fe 3 O 4 microbeads that had weak ferromagnetism. It is found that the Fe 3 O 4 microbeads played a pivotal role in enhancing photocatalytic activity of C 60 @Pt as the weak local magnetic field it induced around C 60 @Pt contributed to promoting the separation of photo-excited electrons from electron-donor. This strategy effectively boosted hydrogen evolution rate and AQE of C 60 @Pt. [Display omitted] • Modulate activity of C 60 -based photocatalyst via connecting weak magnetic substance. • Promote separation of photo-excited electrons by inducing weak local magnetic field. • AQE was boosted up to 2.5 times with the coupling of weak magnetic substance. • Hydrogen evolution improved up to 3.7 times when connecting weak magnetic substance. • Remarkably improve HER photocatalytic robustness of C 60 -based photocatalyst. [ABSTRACT FROM AUTHOR]