0D/2D heterojunctions,e specially quantum dots (QDs)/nanosheets (NSs) have attracted significant attention for use of photoexcited electrons/holes due to their high charge mobility.H erein, unprecedent heterojunctions of vanadate (AgVO 3 ,B iVO 4 ,I nVO 4 and CuV 2 O 6 )Q Ds/graphitic carbon nitride (g-C 3 N 4 )N Ss exhibiting multiple unique advances beyond traditional 0D/2D composites have been developed. The photoactive contribution, up-conversion absorption, and nitrogen coordinating sites of g-C 3 N 4 NSs,h ighly dispersed vanadate nanocrystals,aswell as the strong coupling and band alignment between them lead to superior visible-light-driven photoelectrochemical (PEC) and photocatalytic performance, competing with the best reported photocatalysts.T his work is expected to provide anew concept to construct multifunctional 0D/2D nanocomposites for al arge variety of opto-electronic applications,n ot limited in photocatalysis.For decades,0-dimensional (0D) semiconductive QDs have attracted great attention due to their unique advantages of small size (< 10 nm), large surface area, short effective charge-transfer length and size-tunable optoelectronics, [1] which make them highly promising in using the photoexcited charges in the field of photodetectors,p hototransistors, photovoltaic devices,a nd photocatalysts.[2] However,s everal drawbacks largely restrict their practical applications. [1a,2b, 3] First, QDs are vulnerable to self-aggregation;a bundant surface defects make them unstable in comparison with their bulk counterparts;m oreover,t he high photoluminescence of QDs results in heavy recombination of photoexcited charges.[4] One of the most efficient routes to solve these problems is to load QDs onto ultrathin 2-dimensional (2D) NSs (e.g. graphene) to form a0 D/2D nanocomposite. [5] Interactions between two moieties can make QDs more dispersive and stable,w hile the accelerated charge transfer facilitated by 2D NSs can effectively quench the photoluminescence of QDs,thereby suppressing the recombination of photoexcited charges.T hus,s ubstantially enhanced optoelectronic performance is achieved by the 0D/2D composites in efficient utilization of photoexcited charges. [5] Recently,0 D/2D composite photocatalysts/photoelectrodes have been greatly developed, in which the coupling of QDs and graphene NSs is the most successful illustration. Due to the large surface area and high electrical conductivity of graphene,t he loaded semiconductive QDs (nanocrystals) are endowed with superior charge transfer and separation capability,t hereby presenting greatly promoted photocatalytic activity or/and photocurrent.[6] Forexample,Y uand coworkers [6a] loaded TiO 2 nanocrystals (< 10 nm) on graphene NSs,which displayed the best apparent quantum efficiency of 9.7 %a t3 65 nm;F ang et al.[6b] and Liu and co-workers [6c] respectively incorporated CdS QDs onto graphene NSs, bringing enhanced photocatalytic and PEC performance. However,t he largely consumed graphene NSs (volume ratio even higher than 50...

Semiconductive property of elementary substance is an interesting and attractive phenomenon. We obtain a breakthrough that fibrous phase red phosphorus, a recent discovered modification of red phosphorus by Ruck et al., can work as a semiconductor photocatalyst for visible-light-driven hydrogen (H2 ) evolution. Small sized fibrous phosphorus is obtained by 1) loading it on photoinactive SiO2 fibers or by 2) smashing it ultrasonically. They display the steady hydrogen evolution rates of 633 μmol h(-1)  g(-1) and 684 μmol h(-1)  g(-1) , respectively. These values are much higher than previous amorphous P (0.6 μmol h(-1)  g(-1) ) and Hittorf P (1.6 μmol h(-1)  g(-1) ). Moreover, they are the highest records in the family of elemental photocatalysts to date. This discovery is helpful for further understanding the semiconductive property of elementary substance. It is also favorable for the development of elemental photocatalysts.

A new visible‐light responsive metallic photocatalyst, nanostructured MoO2, has been discovered. The metallic nature of MoO2 is confirmed by valance X‐ray photoelectron spectroscopy spectrum and theoretical calculations. However, MoO2 itself shows only moderate activity due to the serious charge recombination, a general disadvantage of metallic photocatalysts. The findings suggest that its effective charge diffusion length Lp is smaller than 1.0 nm while the separation efficiency ηsep is less than 10%. Therefore, only the periphery of the metallic MoO2 can effectively contribute to photocatalysis. This limitation is overcome by integrating MoO2 in a hydrothermal carbonation carbon (HTCC) matrix (mainly contains semiconductive polyfuran). This simple chemical modification brings two advantages: (i) an internal electric field is formed at the interface between MoO2 and HTCC due to their appropriate band alignment; (ii) the nanostructured MoO2 and the HTCC matrix are intertwined with each other intimately. Their small size and large contact area promote charge transfer, especially under the internal electric field. Therefore, the separation rate of photoexcited charge carrier in MoO2 is greatly enhanced. The activity increases by 2.4, 16.8, and 4.0 times in photocatalytic oxygen evolution, dyes degradation, and photoelectrochemicl cell, respectively. The new approach is helpful for further development of metallic photocatalysts.

An efficient method is developed for the synthesis of single crystalline fibrous phosphorus submicron materials. Via the chemical vapor deposition (CVD) technique, fibrous phosphorus fibers with diameters from ∼150 nm to 2 μm were prepared directly from amorphous red phosphorus. The as-prepared fibrous phosphorus exhibited interesting photocatalytic properties.

Hydrogen from photocatalytic water splitting is a sustainable and renewable source of clean energy.

Photocatalytic conversion of nitrogen (N 2 ) to ammonia (NH 3 ) requires strong binding of N 2 onto the catalyst surface and the generation of photoexcited electrons to activate the NN bond. In this study, Fe is doped into BiOBr nanosheets, where the photoexcited electrons have enough energy to break the NN bond. The presence of Fe induces the formation of oxygen vacancies (OVs) in its vicinity, making it a photoexcited electronrich region. The reduced Fe species effectively donates its available 3d orbital electron into the π N−N antibonding orbital to activate the adsorbed N 2 . With Fe as the active site, the N 2 fixation rate of Fe-doped BiOBr is enhanced by eight times. This work provides a sustainable alternative for N 2 photofixation and strategies for the catalyst design.

Suppression of surface states is one of the general issues for metal oxide photoanodes in water oxidation. For hematite (α-Fe 2 O 3 ), the surface states are mainly attributed to Fe 3+ /Fe 2+ redox couples in oxygen deficient regions (surface oxygen vacancies). To date, most of the passivation overlayers against surface states are metal oxides. However, oxygen vacancies are prevalent for most metal oxides. This is because their formation in metal oxides is often thermodynamically favorable. In contrast, the formation of oxygen vacancies is more energy-consuming when oxygen atoms are covalently bonded. On the basis of this understanding, we propose a new strategy to transform the surface of Fe 2 O 3 into amorphous iron phosphate (denoted "Fe-Pi"), where the oxygen atoms are "covalently fixed" in phosphate (PO 4 3−). As a result, the oxygen vacancies are decreased and the surface states are effectively suppressed. The onset potential of corresponding photoanode shifts negatively by 0.15 V and the photocurrent density increases by 4.2 (simulated sunlight) and 4.1 (visible light) times. The suppression of surface states by amorphous Fe-Pi overlayer is then confirmed by series of electrochemical analysis. This work is expected to create new opportunities for optimizing the performance of Fe 2 O 3 and other metal oxide photoanodes.

A new photocatalyst was prepared by loading 1 wt% of a platinum cobalt alloy on CdS via a simple polyol reduction method. XRD measurements confirmed the composition of the alloy as Pt 3 Co. Results from transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) measurements showed that Pt 3 Co nanoparticles with an average size of 4 nm were uniformly assembled on the surface of CdS. It was found that the activity of Pt 3 Co-CdS was approximately two times higher than that of Pt-CdS for photocatalytic H 2 evolution. Photochemical measurements suggested that the high activity could be attributed to a better accumulation of photoexcited electrons and the higher conductivity of Pt 3 Co-CdS than that of Pt-CdS. The Pt 3 Co alloy cocatalyst was also loaded on TiO 2 , another widely used photocatalyst, and it also exhibited higher activity than pure Pt loaded on TiO 2 . This demonstrates the potential of Pt 3 Co as a universal cocatalyst.