Themed collection Water splitting and photocatalysis

Guest editors Shannon Boettcher, Thomas Mallouk and Frank Osterloh introduce this Journal of Materials Chemistry A themed issue on water splitting and photocatalysis.

The solar-powered electrochemical energy storage strategy integrates the solar energy conversion, storage and distribution functions into a single device.

The recent development of tantalum (oxy)nitride based photoanodes is summarized and their future trends are also discussed.

Artificial photosynthesis, i.e. the chemical transformation of sunlight, water and carbon dioxide into high-energy-rich fuels is one of the key sustainable energy technologies to enable a carbon-free, storable and renewable source of energy.

Semiconductor/liquid junctions can help better understand the photovoltage “potential” of PbS QD solids.

Oxygen-deficient metal oxides prepared by electrochemical method show substantially enhanced photoactivity due to improved efficiency of charge separation and injection.

Metastable CoO_xS_y electrocatalysts for the hydrogen evolution reaction were prepared by anion exchange. Lightly doped CoO_xS_0.18 is 2–3 times more active than either end-member of the substitution series due to optimized H adsorption energy.

A novel titanate perovskite with orthogonal hierarchical nanostructure morphology was evaluated for the first time as a photocatalyst for hydrogen production from water.

GaAs photocathodes are intrinsically stabilized by surface As during hydrogen evolution at −15 mA cm⁻² in acid; etching at <0.5 nm h⁻¹ while maintaining performance.

Stack deposition-annealing (SDA) synthesis of photocatalytic CuWO₄ thin films via sequential ALD of WO₃/CuO and post-ALD annealing.

A facile nonpolar organic solution approach has been developed for a high performance hematite photoanode at a low sintering temperature (550 °C).

Burying platinum black silicon photocathodes provides an atomically clean Pt catalyst/Si interface free of oxide or other phases.

Widespread deployment of solar fuel generators requires the development of efficient and scalable functional materials, especially for photoelectrocatalysis of the oxygen evolution reaction.

Ti:CuSiO₃ and Si:Cu₃TiO_x are identified as promising photocathode materials with improved stability and high photocurrent densities.

Photoelectrochemical reduction of CO₂ to form useful chemicals is an increasingly studied avenue for harnessing and storing solar energy.

Single Cu(II) and Fe(III) surface catalytic sites dramatically enhance the activity of rutile TiO₂ in photocatalytic degradation of 4-chlorophenol.

As a visible light active p-type semiconductor, CuBi₂O₄ is of interest as a photocatalyst for the generation of hydrogen fuel from water.

A multi-physics model of a planar water-splitting photoelectrode was developed, validated, and used to identify and quantify the most significant materials-related bottlenecks in photoelectrochemical device performance.

Investigation of CuNb_1−xTa_xO₃ has led to new insights into the visible-light photocurrents and photocatalytic activities of solid solutions.

Thin (~50 nm) film hematite photoanodes doped with different dopants at a concentration of 1 cation% display internal solar to chemical (ISTC) conversion efficiency in the following order: Sn > Nb > Si > Pt > Zr > Ti > Zn > Ni > Mn.

Organic solvents with varied electrophoretic mobility have been employed for deposition of nanocrystalline ZnO:Co particles onto fluorinated tin oxide supports.

Heteroepitaxial hematite thin film photoanodes were fabricated, characterized, and shown to be a model system for fundamental studies into solar water splitting.

16 crystalline metal oxide nanoparticulate systems are adhered to an electrode surface using a conventional drop-casting method and measured for their activity for the oxygen evolution reaction.

More than 30% enhancement in photocurrent is achieved by separating light confinement and absorption sites within the solar cell.

Colloidal nanoparticles of a cobalt–molybdenum alloy were synthesized and found to be active electrocatalysts for the hydrogen evolution reaction in alkaline aqueous solutions.

We have prepared a solid-state heterojunction photocatalyst, in which zinc rhodium oxide (ZnRh₂O₄) and bismuth vanadium oxide (Bi₄V₂O₁₁) as hydrogen (H₂) and oxygen (O₂) evolution photocatalysts, respectively, were connected with silver (Ag, ZnRh₂O₄/Ag/Bi₄V₂O₁₁).

Porous n-type Fe₂V₄O₁₃ films were prepared by a simplified successive ion layer adsorption method and the photogenerated holes in the films can be efficiently utilized to oxidize water to oxygen.

We present a soft-templating synthesis of amorphous ordered mesoporous tantalates with incorporated alkali earth metals for photocatalytic water splitting.

Close-spaced vapor transport provides GaAs_1−xP_x with controlled composition and competitive electronic properties.

Charge transfer dynamics in WO₃ photoelectrodes: hydroxyl radicals are the primary water oxidation intermediates generated via valence band hole injection.

The properties of cyanoporphyrins make them good candidates for sensitizers in photoelectrosynthetic cells. A new procedure for preparation of these has been developed and two cyanoporphyrins have been evaluated as sensitizers for photoanodes.

Kinetics measurements are used to clarify the effect of Co-Pi on solar water splitting by Co-Pi/α-Fe₂O₃ composite photoanodes.

Visible light driven water splitting in a dye-sensitized photoelectrochemical cell (DSPEC) based on a phosphonic acid-derivatized donor–π–acceptor (D–π–A) organic dye (P–A–π–D) is described with the dye anchored to an FTO|SnO₂/TiO₂ core/shell photoanode in a pH 7 phosphate buffer solution.

A guideline to achieve efficient photocatalytic water splitting is presented using theoretical simulations of particulate semiconductors decorated with metal particles.

SrTiO₃ doped with Al and treated with SrCl₂ flux showed an apparent quantum efficiency of 30% at 360 nm in the photocatalytic overall water splitting reaction.

p-Type delafossite CuFeO₂ has recently been reported as a promising candidate for direct photoelectrochemical solar water reduction in alkaline conditions.

WO₃ electrodes were synthesized via a sol–gel route followed by the photoelectrochemical deposition of a solid state FeOOH oxygen-evolution catalyst (OEC) to observe its effects on electrode stability and selectivity towards the oxygen evolution reaction (OER).

Periodate is used as an alternative oxidant in the rapid screening of new potential water oxidation catalyst material powders.

Perylene-3,4-dicarboximide (PMI) based chromophores are explored for use in photoelectrochemical cells (PECs) for solar fuels generation.

When the reactivities of crystals of the same orientation of (Bi_1−0.5xNa_0.5x)(V_1−xMo_x)O₄, with x = 0.05 and x = 0.175, are compared, the monoclinic (x = 0.05) sample is more reactive.

An in situ surface alkalization over g-C₃N₄ achieves 14-fold enhancement in photocatalytic H₂ evolution.

(Ga_1−xZn_x)(N_1−xO_x) nanocrystals with a wide range of compositions and band gaps are formed by topotactic nucleation at ZnO/ZnGa₂O₄ interfaces.

Long exposure of BiVO₄ photoanodes to light under open circuit conditions (photocharging) results in the record high current densities for undoped and uncatalyzed BiVO₄.

Low frequency capacitance measurements allow decoupling direct hole transfer from the valence band and indirect hole transfer from surface states.

Photocatalytic hydrogen evolution activity of CdS QDs is 175 times higher in pH neutral water when surface capping ligands are removed.