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Photocorrosion stable WO(3) nanowire arrays are synthesized by a solvothermal technique on fluorine-doped tin oxide coated glass. WO(3) morphologies of hexagonal and monoclinic structure, ranging from nanowire to nanoflake arrays, are tailored by adjusting solution composition with growth along the (001) direction. Photoelectrochemical measurements of illustrative films show incident photon-to-current conversion efficiencies higher than 60% at 400 nm with a photocurrent of 1.43 mA/cm(2) under AM 1.5G illumination. Our solvothermal film growth technique offers an exciting opportunity for growth of one-dimensional metal oxide nanostructures with practical application in photoelectrochemical energy conversion.

As inspired by natural photosynthesis, semiconductor-based photocatalytic water splitting into hydrogen and oxygen has attracted extensive attention, which provides a promising and clean method to convert solar energy into chemical fuel, for alleviating human's excessive reliance on fossil fuels. [1][2][3] For the water splitting process, the half-reaction of water oxidation to oxygen has been well recognized as the rate-limiting step for its four-electron oxidation process and high activation energy barrier (≈700 mV) for O-O bond formation, [4,5] which thus remains as the main challenge to achieve highly efficient overall water splitting. Although enormous efforts have been dedicated to develop photocatalysts for improved water oxidation performances in the past decades, by far only a few photocatalysts (e.g., WO 3 , BiVO 4 , and Ag 3 PO 4 , etc.) have been proven to be efficient for lightdriven oxygen evolution from water. [5][6][7][8] Worse still, several drawbacks always limit their practical application in oxygen-generating photocatalytic systems, including poor photostability, low charge carrier mobility, and high costs of raw materials. Since the pioneering work reported in 2009 by Wang et al., [9] metal-free graphitic carbon nitride (g-C 3 N 4 ) with a 2D conjugated structure has been intensively investigated for photocatalytic water redox reactions, owing to its earth-abundance, environmental friendliness, chemical stability, and suitable thermodynamical potentials for both hydrogen and oxygen evolution reactions. [10][11][12] In the past ten years, various strategies, including thermodynamic (such as doping with heteroatoms, [13][14][15][16] engineering defects with nitrogen vacancies or carbon vacancies, [17,18] etc.) and kinetic (such as compositing with other semiconductors, [7,[19][20][21][22] morphology design, [23][24][25][26][27] and loading cocatalysts, [28][29][30] etc.) modifications, have emerged to enhance the photocatalytic hydrogen evolution activity of g-C 3 N 4 and a high quantum yield of 34.4% at 400 nm has been achieved. [31] However, only very few results have been reported on g-C 3 N 4 based photocatalysts for water oxidation, and most of them were focused on surface modification by loading cocatalysts, such as cobalt (hydr)oxide and selenide, [32][33][34] etc., onto g-C 3 N 4 . Unfortunately, the photocatalytic oxygen evolution Electronic structure greatly determines the band structures and the charge carrier transport properties of semiconducting photocatalysts and consequently their photocatalytic activities. Here, by simply calcining the mixture of graphitic carbon nitride (g-C 3 N 4 ) and sodium borohydride in an inert atmosphere, boron dopants and nitrogen defects are simultaneously introduced into g-C 3 N 4 . The resultant boron-doped and nitrogen-deficient g-C 3 N 4 exhibits excellent activity for photocatalytic oxygen evolution, with highest oxygen evolution rate reaching 561.2 µmol h −1 g −1 , much higher than previously reported g-C 3 N 4 . It is well evidenced that with c...

With the intense interest in inorganic cesium lead halide perovskites and their nanostructures for optoelectronic applications, high-quality crystalline nanomaterials with controllable morphologies and growth directions are desirable. Here, we report a vapor-phase epitaxial growth of horizontal single-crystal CsPbX (X = Cl, Br, I) nanowires (NWs) and microwires (MWs) with controlled crystallographic orientations on the (001) plane of phlogopite and muscovite mica. Moreover, single NWs, Y-shaped branches, interconnected NW or MW networks with 6-fold symmetry, and, eventually, highly dense epitaxial network of CsPbBr with nearly continuous coverage were controllably obtained by varying the growth time. Detailed structural study revealed that the CsPbBr wires grow along the [001] directions and have the (100) facets exposed. The incommensurate heteroepitaxial lattice match between the CsPbBr and mica crystal structures and the growth mechanism of these horizontal wires due to asymmetric lattice mismatch were proposed. Furthermore, the photoluminescence waveguiding and good performance from the photodetector device fabricated with these CsPbBr networks demonstrated that these well-connected CsPbBr NWs could serve as straightforward platforms for fundamental studies and optoelectronic applications.

Photocatalytic hydrogen production using semiconductor materials is one of the ideal processes for direct solar energy conversion. Sulphide semiconductor photocatalysts have attracted much attention due to their excellent solar spectrum responses and high photocatalytic activities. This article presents recent research progress in the development of visible light driven sulphide photocatalysts, focusing on the expansion of solar spectrum response and enhancement of charge separation efficiency. As is known, the ultimate goal of photocatalytic hydrogen production is to meet the practical energy demand of human beings. Thus, design of highly efficient and low cost sulphide photocatalysts with excellent sunlight response is highly desired. So we also highlight the crucial issues in the development of highly efficient sulphide photocatalysts without noble metal cocatalysts. The present paper is expected to provide important scientific reference for future works. Finally, the challenges and perspectives in this area are also discussed.

A novel method for the preparation of a CdS photocatalyst is presented. In this method, freshly prepared CdO obtained by decomposing cadmium acetate at a certain temperature was subjected to thermal treatment in the presence of H2S, which results in the formation of a highly stable and active CdS photocatalyst. In comparison to conventional preparation methods, CdS prepared by our method was found to be stable against both air oxidation and photocorrosion during a photocatalytic reaction. Most importantly, the special nanostep structure was observed at the surface of the sulfide photocatalyst, which was demonstrated to be crucial for the remarkable enhancement of photocatalytic hydrogen production. The apparent quantum yield at 420 nm and the energy conversion efficiency in the whole visible light region were determined to be 24.1% and 6.35%, respectively, in our experimental conditions.

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