Water Splitting Photovoltaic-Photoelectrochemical GaAs/InGaAsP - WO3/BiVO4 Tandem Cell with Extremely Thin Absorber Photoanode Structure

We demonstrate highly efficient solar hydrogen generation via water splitting by photovoltaicphotoelectrochemical (PV-PEC) tandem device based on GaAs/InGaAsP (PV cell) and WO3/BiVO4 core/shell nanorods (PEC cell). We utilized extremely thin absorber (ETA) concept to design the WO3/BiVO4 core/shell heterojunction nanorods and obtained the highest efficiencies of photo-induced charge carriers generation, separation and transfer that are possible for the WO3/BiVO4 material combination. The PV-PEC tandem shows stable water splitting photocurrent of 6.56 mA cm-2 under standard AM1.5G solar light that corresponds to the record solar-to-hydrogen (STH) conversion efficiency of 8.1%

Single-Source Bismuth (Transition Metal) Polyoxovanadate Precursors for the Scalable Synthesis of Doped BiVO4 Photoanodes.

Single-source precursors are used to produce nanostructured BiVO4 photoanodes for water oxidation in a straightforward and scalable drop-casting synthetic process. Polyoxometallate precursors, which contain both Bi and V, are produced in a one-step reaction from commercially available starting materials. Simple annealing of the molecular precursor produces nanocrystalline BiVO4 films. The precursor can be designed to incorporate a third metal (Co, Ni, Cu, or Zn), enabling the direct formation of doped BiVO4 films. In particular, the Co- and Zn-doped photoanodes show promise for photoelectrochemical water oxidation, with photocurrent densities >1 mA cm-2 at 1.23 V vs reversible hydrogen electrode (RHE). Using this simple synthetic process, a 300 cm2 Co-BiVO4 photoanode is produced, which generates a photocurrent of up to 67 mA at 1.23 V vs RHE and demonstrates the scalability of this approach.We thank the following for financial support: China Scholarship Council (H.L.), the Cambridge Trusts (Vice Chancellor’s Award) and the Winton Programme for the Physics of Sustainability (V.A.), A*STAR Graduate Scholarship (Overseas) (N.L.), Imperial College Research Fellowship (A.R.), Christian Doppler Research Association and the OMV Group (E.R), Herchel Smith Research Fund (S.D.P

Pulsed DC magnetron sputtering deposition of crystalline photocatalytic titania coatings at elevated process pressures

© 2017 Elsevier Ltd The use of elevated process pressures is described in the magnetron sputter deposition of titanium dioxide photocatalytic coatings to enable the direct low-temperature formation of the most photoactive titania crystal phase; anatase. Most other works on this subject deal with relatively low ‘conventional’ pressures (0.1–0.5 Pa). However, the present work describes pulsed DC reactive magnetron sputtering deposition of titanium dioxide thin films at process pressures in the range 2–5 Pa in a purpose-built sputtering rig. The influence of the other deposition conditions, such as pulse frequency and duty cycle, is also discussed. Additionally, a series of N-doped titania coatings was produced by using air as the reactive gas. The morphological and compositional properties of the coatings were studied using energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Wettability of the films was studied through measurement of water contact angles under UV light irradiation. Photocatalytic properties of the samples were assessed through the degradation of two model pollutants, methylene blue and stearic acid, under UV light irradiation. The results showed that elevated process pressures (4 Pa and above) allow the direct deposition of anatase titania films, without additional heat treatment, while amorphous titania tends to form at lower process pressures

Intelligent Chiral Sensing Based on Supramolecular and Interfacial Concepts

Of the known intelligently-operating systems, the majority can undoubtedly be classed as being of biological origin. One of the notable differences between biological and artificial systems is the important fact that biological materials consist mostly of chiral molecules. While most biochemical processes routinely discriminate chiral molecules, differentiation between chiral molecules in artificial systems is currently one of the challenging subjects in the field of molecular recognition. Therefore, one of the important challenges for intelligent man-made sensors is to prepare a sensing system that can discriminate chiral molecules. Because intermolecular interactions and detection at surfaces are respectively parts of supramolecular chemistry and interfacial science, chiral sensing based on supramolecular and interfacial concepts is a significant topic. In this review, we briefly summarize recent advances in these fields, including supramolecular hosts for color detection on chiral sensing, indicator-displacement assays, kinetic resolution in supramolecular reactions with analyses by mass spectrometry, use of chiral shape-defined polymers, such as dynamic helical polymers, molecular imprinting, thin films on surfaces of devices such as QCM, functional electrodes, FET, and SPR, the combined technique of magnetic resonance imaging and immunoassay, and chiral detection using scanning tunneling microscopy and cantilever technology. In addition, we will discuss novel concepts in recent research including the use of achiral reagents for chiral sensing with NMR, and mechanical control of chiral sensing. The importance of integration of chiral sensing systems with rapidly developing nanotechnology and nanomaterials is also emphasized

High-performance and stable photoelectrochemical water splitting cell with organic-photoactive-layer-based photoanode

Considering their superior charge-transfer characteristics, easy tenability of energy levels, and low production cost, organic semiconductors are ideal for photoelectrochemical (PEC) hydrogen production. However, organic-semiconductor-based photoelectrodes have not been extensively explored for PEC water-splitting because of their low stability in water. Herein, we report high-performance and stable organic-semiconductors photoanodes consisting of p-type polymers and n-type non-fullerene materials, which is passivated using nickel foils, GaIn eutectic, and layered double hydroxides as model materials. We achieve a photocurrent density of 15.1 mA cm???2 at 1.23 V vs. reversible hydrogen electrode (RHE) with an onset potential of 0.55 V vs. RHE and a record high half-cell solar-to-hydrogen conversion efficiency of 4.33% under AM 1.5 G solar simulated light. After conducting the stability test at 1.3 V vs. RHE for 10 h, 90% of the initial photocurrent density are retained, whereas the photoactive layer without passivation lost its activity within a few minutes

Code of Corporate Ethics as a Tool for Developing the Potential of Enterprises

The key role in the creation, maintenance, and development of corporate ethics is played by codes of corporate ethics. The relevance of the problem lies in determining approaches to the creation of the content and the importance of codes of corporate ethics as a tool for developing the potential of the enterprise. Each company defines its own tasks, for which it intends to use such a tool as the code of corporate ethics. Nevertheless, the creation of the code, admittedly, extends beyond writing the text of the document. There is a specific implementation of such documents: it is impossible to force one to comply with the code of ethics. The purpose of the study is to determine approaches to the creation of the content and the importance of codes of corporate ethics as a tool for developing the potential of an enterprise. The study defines the essence of the “code of corporate ethics”. Classification of existing codes of corporate ethics is conducted. Universal codes and ethical codes, including professional and corporate ones, are highlighted. The main functions performed by corporate codes in organisations are identified and investigated, including the factors that determine the content of the code. Approaches to creating ethical corporate codes are covered. Two versions of the code, such as declarative and detailed, are considered, which is reflected in examples of actual codes. The classification of existing approaches to the codes of corporate ethics is given to build a methodological base. The study describes the importance of each employee's adoption of the code of corporate ethics, since only under this condition will it be implemented. Based on the above, it is recommended that at the stage of creating the code, procedures should be provided that would include all employees of the company in developing the document, if possibl

Corporate Law and Corporate Culture as Means of Influencing the Efficiency of Corporations

Corporate law and corporate culture are a set of means of multidirectional influence on the efficiency of corporate legal entities, they regulate relations that may arise during the creation, performance, and termination of economic activities, determine the means, forms, and structure of the organisation of activities. The purpose of the study is to determine the features and basic principles under which corporate law and corporate culture develop patterns that facilitate achieving the goals and optimising certain processes in the activities of corporate legal entities. The research methodology is based on the methods of logical analysis, critical analysis of scientific literature, and practical experience. The results of the study allowed considering corporate culture and corporate law as specific means of modelling personnel behaviour or managing it. These tools pose scientific originality and allow achieving such an image of personnel interaction that is acceptable for the efficiency of corporate legal entities. The basic result that poses originality is the structuring of corporate culture and corporate law, implemented in the context of: a model framework that defines the features and basic principles of influencing personnel behaviour; patterns of behaviour in the organisation that determine the internal environment, where each employee invests strength in a common goal (efficiency of the enterprise). The study of the model basis of corporate culture and corporate law, patterns of behaviour in the organisation allowed identifying the basic principles which positively affect the efficiency of corporate legal entities. The highlighted principles of corporate culture and corporate law positively impact the efficiency of corporate legal entities if clan or adhocratic types of corporate culture are developed. The practical value of the study is to identify elements for software development that will help corporate legal entities involve employees in work processes, create and strengthen corporate cultur