A hole-selective hybrid TiO layer for stable and low-cost photoanodes in solar water oxidation.

The use of conductive and corrosion-resistant protective layers represents a key strategy for improving the durability of light absorber materials in photoelectrochemical water splitting. For high performance photoanodes such as Si, GaAs, and GaP, amorphous TiO protective overlayers, deposited by atomic layer deposition, are conductive for holes via a defect band in the TiO. However, when coated on simply prepared, low-cost photoanodes such as metal oxides, no charge transfer is observed through amorphous TiO.

One-Step Hydrothermal Synthesis of Sn-Doped SbSe for Solar Hydrogen Production.

Antimony selenide (SbSe) has recently been intensively investigated and has achieved significant advancement in photoelectrochemical (PEC) water splitting. In this work, a facile one-step hydrothermal method for the preparation of Sn-doped SbSe photocathodes with improved PEC performance was investigated. We present an in-depth study of the performance enhancement in Sn-doped SbSe photocathodes using capacitance-voltage (CV), drive-level capacitance profiling (DLCP), and electrochemical impedance spectroscopy (EIS) techniques.

Amine-Rich Hydrogels for Molecular Nanoarchitectonics of Photosystem II and Inverse Opal TiO toward Solar Water Oxidation.

Solar water oxidation is a crucial process in light-driven reductive synthesis, providing electrons and protons for various chemical reductions. Despite advances in light-harvesting materials and cocatalysts, achieving high efficiency and stability remains challenging. In this study, we present a simple yet effective strategy for immobilizing natural photosystems (PS) made of abundant and inexpensive elements, using amine-rich polyethylenimine (PEI) hydrogels, to fabricate organic/inorganic hybrid photoanodes.

Solar Biomass Reforming and Hydrogen Production with Earth-Abundant Si-Based Photocatalysts.

Efficient electrochemical hydrogen production and biomass refinery are crucial for the decarbonization of various sectors. However, their energy-intensive nature and low efficiency have hindered their practical application. In this study, earth-abundant and non-toxic photocatalysts that can produce hydrogen and reform biomass efficiently, utilizing unlimited solar energy, are presented.

Prevalence and Risk Factors of Depression in Patients with Rheumatic Disease in South Korea during the COVID-19 Pandemic.

This study aimed to examine the prevalence and risk factors of depression among patients with rheumatic diseases (RDs) during the coronavirus disease 2019 (COVID-19) pandemic. This study adopted a cross-sectional design, and 160 outpatients with RDs in one university hospital in South Korea were sampled using the convenience sampling method. Data were collected from May to July 2021 using a structured questionnaire.

Synthesis of hexagonal rosettes of g-CN with boosted charge transfer for the enhanced visible-light photocatalytic hydrogen evolution and hydrogen peroxide production.

Photocatalytic sustainable fuel production attracted extensive attention because of the urgent need of the society to shift from fossil fuels to solar fuels. Herein, the synthesis of hexagonal rosettes of g-CN with an efficient performance toward hydrogen evolution and hydrogen peroxide production as the two kinds of solar fuels were reported. The hexagonal rosettes of g-CN were simply fabricated via controlled solid-state polymerization of three-dimensional hexagonal rosettes of cyanuric acid-melamine adduct at 500 °C.

Catalytic Multilayers for Efficient Solar Water Oxidation through Catalyst Loading and Surface-State Passivation of BiVO Photoanodes.

We studied the kinetics of photoelectrochemical (PEC) water oxidation using a model photoanode BiVO modified with various water oxidation catalysts (WOCs) by electrochemical impedance spectroscopy. In particular, we prepared BiVO photoanodes with catalytic multilayers (CMs), where cationic polyelectrolytes and anionic polyoxometalate (POM) WOCs were assembled in a desired amount at a nanoscale precision, and compared their performance with those with well-known WOCs such as cobalt phosphate (CoPi) and NiOOH. Our comparative kinetics analysis suggested that the deposition of the CMs improved the kinetics of both the photogenerated charge carrier separation/transport in bulk BiVO due to passivation of surface recombination centers and water oxidation at the electrode/electrolyte interface due to deposition of efficient molecular WOCs.

Interface Engineering of Hematite with Nacre-like Catalytic Multilayers for Solar Water Oxidation.

An efficient water oxidation photoanode based on hematite has been designed and fabricated by tailored assembly of graphene oxide (GO) nanosheets and cobalt polyoxometalate (Co-POM) water oxidation catalysts into a nacre-like multilayer architecture on a hematite photoanode. The deposition of catalytic multilayers provides a high photocatalytic efficiency and photoelectrochemical stability to underlying hematite photoanodes. Compared to the bare counterpart, the catalytic multilayer electrode exhibits a significantly higher photocurrent density and large cathodic shift in onset potential (∼369 mV) even at neutral pH conditions due to the improved charge transport and catalytic efficiency from the rational and precise assembly of GO and Co-POM.

Semiconducting Synthetic Melanin-Based Organic/Inorganic Hybrid Photoanodes for Solar Water Oxidation.

We report the development of semiconducting melanin-based organic/inorganic hybrid photoanodes for solar water oxidation. Synthetic melanin thin-film incorporating polyoxometalate (POM) water oxidation catalysts (WOCs) are readily deposited on the surface of various n-type inorganic semiconductors (e.g.

WO/Conducting Polymer Heterojunction Photoanodes for Efficient and Stable Photoelectrochemical Water Splitting.

An efficient and stable heterojunction photoanode for solar water oxidation was fabricated by hybridization of WO and conducting polymers (CPs). Organic/inorganic hybrid photoanodes were readily prepared by the electropolymerization of various CPs and the codeposition of tetraruthenium polyoxometalate (RuPOM) water-oxidation catalysts (WOCs) on the surface of WO. The deposition of CPs, especially polypyrrole (PPy) doped with RuPOM (PPy:RuPOM), resulted in a remarkably improved photoelectrochemical performance by the formation of a WO/PPy p-n heterojunction and the incorporation of efficient RuPOM WOCs.

Application of immobilized nanotubular TiO(2) electrode for photocatalytic hydrogen evolution: reduction of hexavalent chromium (Cr(VI)) in water.

In this study, immobilized TiO(2) electrode is applied to reduce toxic Cr(VI) to non-toxic Cr(III) in aqueous solution under UV irradiation. To overcome the limitation of powder TiO(2), a novel technique of immobilization based on anodization was applied and investigated under various experimental conditions. The anodization was performed at 20V-5 degrees C for 45min with 0.