Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

To better utilize the sunlight for efficient solar energy conversion, the research on visible-light active photocatalysts has recently attracted a lot of interest. The photosensitization of transition metal oxides is a promising approach for achieving effective visible-light photocatalysis. This review article primarily discusses the recent progress in the realm of a variety of nanostructured photosensitizers such as quantum dots, plasmonic metal nanostructures, and carbon nanostructures for coupling with wide-bandgap transition metal oxides to design better visible-light active photocatalysts. The underlying mechanisms of the composite photocatalysts, e.g., the light-induced charge separation and the subsequent visible-light photocatalytic reaction processes in environmental remediation and solar fuel generation fields, are also introduced. A brief outlook on the nanostructure photosensitization is also given

Review of recent progress in unassisted photoelectrochemical water splitting: from material modification to configuration design

Photoelectrochemical (PEC) energy conversion systems have been considered as a highly potential strategy for clean solar fuel production, simultaneously addressing the energy and environment challenges we are facing. Tremendous research efforts have been made to design and develop feasible unassisted PEC systems that can efficiently split water into hydrogen (H2) and oxygen with only the energy input of sunlight. A fundamental understanding of the concepts involved in PEC water splitting and energy conversion efficiency enhancement for solar fuel production is important for better system design. This review gives a concise overview of the unassisted PEC devices with some state-of-the-art progress toward efficient PEC devices for future sustainable solar energy utilization

Inorganic perovskite photocatalysts for solar energy utilization

The authors acknowledge funding from the Engineering and Physical Research Council for research award EP/K036769/1 and Platform Grant EP/K015540/1. Financial support from the Major Basic Research Program, Ministry of Science and Technology of China (2014CB239401) and the NSFC (51422210, 51629201) is acknowledged. The authors also acknowledge support from The Royal Society Newton Fellowship, NA140077 and The Royal Society Wolfson Merit Award, WRM 2012/R2.The development and utilization of solar energy in environmental remediation and water splitting is being intensively studied worldwide. During the past few decades, tremendous efforts have been devoted to developing non-toxic, low-cost, efficient and stable photocatalysts for water splitting and environmental remediation. To date, several hundreds of photocatalysts mainly based on metal oxides, sulfides and (oxy)nitrides with different structures and compositions have been reported. Among them, perovskite oxides and their derivatives (layered perovskite oxides) comprise a large family of semiconductor photocatalysts because of their structural simplicity and flexibility. This review specifically focuses on the general background of perovskite and its related materials, summarizes the recent development of perovskite photocatalysts and their applications in water splitting and environmental remediation, discusses the theoretical modelling and calculation of perovskite photocatalysts and presents the key challenges and perspectives on the research of perovskite photocatalysts.PostprintPostprintPeer reviewe

Synthesis, properties, and optical applications of noble metal nanoparticle-biomolecule conjugates

Noble metal nanoparticles, such as gold or silver nanoparticles and nanorods, exhibit unique photonic, electronic and catalytic properties. Functionalization of noble metal nanoparticles with biomolecules (e. g., protein and DNA) produces systems that possess numerous applications in catalysis, delivery, therapy, imaging, sensing, constructing nanostructures and controlling the structure of biomolecules. In this paper, the recent development of noble metal nanoparticle-biomolecule conjugates is reviewed from the following three aspects: (1) synthesis of noble metal nanoparticle-biomolecule systems by electrostatic adsorption, direct chemisorption of thiol derivatives, covalent binding through bifunctional linkers and specific affinity interactions; (2) the photonic properties and bioactivation of noble metal nanoparticle-biomolecule conjugates; and (3) the optical applications of such systems in biosensors, and medical imaging, diagnosis, and therapy. The conjugation of Au and Ag nanoparticles with biomolecules and the most recent optical applications of the resulting systems have been focused on

Insight into the liquid state of organo-lead halide perovskites and their new roles in dye-sensitized solar cells

Here we report that organo-lead halide perovskite CH3NH 3PbI(3-x)Clx solution can be used as a new liquid electrolyte in dye-sensitized solar cells (DSCs). We find that the presence of inorganic octahedra of [PbX6]4- (X = I or Cl, or a combination of them) in this perovskite solution can not only remarkably improve the device stability but also enhance the photo-response of DSCs

Complete surface coverage of ZnO nanorod arrays by pulsed electrodeposited CuInS2 for visible light energy conversion

Well-aligned ZnO nanorods were uniformly coated with a layer of CuInS2 nanoparticle photosensitizers using a tailored sequential pulsed electrodeposition. The formation of CuInS2-ZnO heterojunction with well-matched band energy alignment and the superior electron mobility in ZnO nanorods led to a remarkable 3.75 times improved photoelectrochemical performance of the electrode under visible light irradiation

Two-dimensional g-C3N4/Ca2Nb2TaO10 nanosheet composites for efficient visible light photocatalytic hydrogen evolution

Scalable g-CN nanosheet powder catalyst was prepared by pyrolysis of dicyandiamide and ammonium chloride followed by ultra-sonication and freeze-drying. Nanosheet composite that combines the g-CN nanosheets and CaNbTaO nanosheets with various ratios were developed and applied as photocatalysts for solar hydrogen generation. Systematic studies reveal that the g-CN/CaNbTaO nanosheet composite with a mass ratio of 80:20 shows the best performance in photocatalytic H evolution under visible light-irradiation, which is more than 2.8 times out-performing bare g-CN bulk. The resulting nanosheets possess a high surface area of 96\ua0m/g, which provides abundance active sites for the photocatalytic activity. More importantly, the g-CN/CaNbTaO nanosheet composite shows efficient charge transfer kinetics at its interface, as evident by the photoluminescence measurement. The intimate interfacial connections and the synergistic effect between g-CN nanosheets and CaNbTaO nanosheets with cascading electrons are efficient in suppressing charge recombination and improving photocatalytic H evolution performance

Oxygen vacancy induced structural variations of exfoliated monolayer MnO2 sheets

We report findings on the structural stability of exfoliated monolayer MnO2 sheets. Our study reveals that monolayer MnO2 sheets display two specific kinds of structural modification under electron irradiation. An atomic reconstruction (2 x 1) and a phase of MnO, induced by ordered oxygen vacancies, were identified by transmission electron microscopy techniques and further characterized by comparison with density-functional theory calculations. These findings are expected to significantly broaden current knowledge of the structural stability of ultrathin layered sheets

A hybrid TiO2–Ag nanocluster (NC) photoelectrode demonstrating unique wavelength-switchable photocurrents

Chemicals used, fabrication procedure, instrumentation, and photochemical measurements used in experimentsSupporting figures, images, and graph