Synergistic crystal facet engineering and structural control of WO 3 films exhibiting unprecedented photoelectrochemical performance, Nano Energy, http://dx. AbstractWO 3 nanoplate arrays with (002) oriented facets grown on fluorine doped SnO 2 (FTO) glass substrates are tailored by tuning the precursor solution via a facile hydrothermal method. A 2-step hydrothermal method leads to the preferential growth of WO 3 film with enriched (002) facets, which exhibits extraordinary photoelectrochemical (PEC) performance with a remarkable photocurrent density of 3.7 mA cm -2 at 1.23 V vs. revisable hydrogen electrode (RHE) under AM 1.5 G illumination without the use of any cocatalyst, corresponding to ~93% of the theoretical photocurrent of WO 3 . Density functional theory (DFT) calculations together with experimental studies reveal that the enhanced photocatalytic activity and better photostability of the WO 3 films are attributed to the synergistic effect of highly reactive (002) facet 2 and nanoplate structure which facilitates the photo-induced charge carrier separation and suppresses the formation of peroxo-species. Without the use of oxygen evolution cocatalysts, the excellent PEC performance, demonstrated in this work, by simply tuning crystal facets and nanostructure of pristine WO 3 films may open up new opportunities in designing high performance photoanodes for PEC water splitting. Highlights  WO 3 nanoplate arrays with enriched (200) and (002) facets were prepared.

A new type of boron-doped graphitic carbon nitride (B-g-CN) nanosheets was prepared by a benign one-pot thermal polycondensation process. Systematic studies revealed that a B-doping amount of 1 at% into g-CN (1at%B-g-CN) showed the best photocatalytic H evolution activity of 1880 μmol h g under visible light irradiation (>400 nm), which is more than 12 times that of the pristine g-CN bulk. Detailed characterizations revealed that the high photocatalytic performance could be attributed to the combination of band structure engineering and morphological control. B-doping not only reduces the band gap to absorb more visible light but also exhibits a higher surface area of B-g-CN (49.47 m g) as compared to that of g-CN bulk (8.24 m g), which subsequently improve the photocatalytic performance drastically. This work demonstrates a synergistic strategy to prepare efficient metal-free B-g-CN nanosheets as a promising photocatalyst for H evolution under visible light with good stability.

Photocatalysis has attracted much attention in recent years due to its potential in solving energy and environmental issues. Even though numerous achievements have been made, the photocatalytic systems developed to date are still far from practical applications due to the low efficiency and poor durability. Efficient light absorption and charge separation are two of the key factors for the exploration of high performance photocatalytic systems, which is generally difficult to be obtained in a single photocatalyst. The combination of various materials to form heterojunctions provides an effective way to better harvest solar energy and to facilitate charge separation and transfer, thus enhancing the photocatalytic activity and stability. This review concisely summarizes the recent development of visible light responsive heterojunctions, including the preparation and performances of semiconductor/semiconductor junctions, semiconductor/cocatalyst junctions, semiconductor/metal junctions, semiconductor/non-metal junctions, and surface heterojunctions, and their mechanism for enhanced light harvesting and charge separation/transfer.

A new type of visible light active composite containing exfoliated g-C3N4 nanosheets and Ca2Nb2TaO10 nanosheets was prepared. Systematic studies reveal that the g-C3N4/Ca2Nb2TaO10 nanosheet composite with a mass ratio of 80:20 exhibits the best performance in photocatalytic H2 evolution under visible light-irradiation, which is more than 2.8 times out-performing bare g-C3N4 bulk. The enhancement of photocatalytic H2 evolution of the g-C3N4/Ca2Nb2TaO10 composite is attributed to the intimate interfacial connection and synergistic effect between g-C3N4 nanosheets and Ca2Nb2TaO10 nanosheets with cascading electrons for efficient charge recombination suppression. Highlights  Novel g-C3N4/Ca2Nb2TaO10 nanosheet composite was simply prepared by exfoliation-reassembly method.  The hybridization between the g-C3N4 and Ca2Nb2TaO10 nanosheets provides an intimate interfacial connection.  The synergistic effect of g-C3N4 and Ca2Nb2TaO10 nanosheets is exemplified for improving photocatalytic H2 evolution under visible light irradiation.

The development of technologically and economically viable strategies for large-scale fabrication of photoelectrodes is crucial for solar H2 production from photoelectrochemical water splitting. Herein, a low-cost and facile colloidal electrophoretic deposition approach was developed for scalable fabrication of hematite (α-Fe2O3) films. Large-sized uniform films (e.g. 80 mm × 70 mm) with tailored thickness and nanostructures can be easily prepared on conductive substrates within 2 minutes. The resultant films showed a high photocurrent of ∼1.1 mA cm(-2) at 1.23 V(RHE) under standard AM 1.5G illumination, which is among the highest reported values achieved on hematite films prepared using other complex colloidal approaches. The present work will pave a new avenue for fabrication of efficient photoelectrodes toward practically viable solar H2 production.