In any artificial photosynthetic system, the oxidation of water to molecular oxygen provides the electrons needed for the reduction of protons or carbon dioxide to a fuel. Understanding how this four-electron reaction works in detail is important for the development of improved robust catalysts made of Earth-abundant materials, like first-row transition-metal oxides. Here, using time-resolved Fourier-transform infrared spectroscopy and under reaction conditions, we identify intermediates of water oxidation catalysed by an abundant metal-oxide catalyst, cobalt oxide (Co3O4). One intermediate is a surface superoxide (three-electron oxidation intermediate absorbing at 1,013 cm(-1)), whereas a second observed intermediate is attributed to an oxo Co(IV) site (one-electron oxidation intermediate absorbing at 840 cm(-1)). The temporal behaviour of the intermediates reveals that they belong to different catalytic sites. Knowledge of the structure and kinetics of surface intermediates will enable the design of improved metal-oxide materials for more efficient water oxidation catalysis.
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http://dx.doi.org/10.1038/nchem.1874 | DOI Listing |
Food Chem
January 2025
College of Food Science and Engineering, Hainan University, Haikou 570228, China.
Hydrogen peroxide (HO) was used to modify a natural polymer, sesbania gum (SG), to prepare oxidized sesbania gum (OSG) with the aim of investigating the physicochemical properties, antimicrobial activity of polyethylene oxide (PEO), OSG, and ε-poly(lysine) (ε-PL) composite fibre membranes and their applications in fresh-cut mango preservation. The PEO/OSG/ε-PL composite fibre membranes were successfully prepared via solution blow spinning (SBS) technology. The results of a series of characterizations revealed that ε-PL was successfully loaded into the fibrous membranes, exhibited good biocompatibility, and ε-PL was better encapsulated, with the membranes.
View Article and Find Full Text PDFEnviron Technol
January 2025
Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, Guilin University of Technology, Guilin, People's Republic of China.
P-chlorophenol (4-CP) and hexavalent chromium (Cr (VI)) are predominant contaminants in industrial effluents, eliciting substantial environmental and human health concerns. As a strong oxidant, Cr (Ⅵ) has the potential to facilitate the removal of 4-CP. However, the specific removal effect remains unclear.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
CPRAC Research Center, Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques, Bou-Ismail CP, Tipaza, 42004, Algeria.
The aim of the present work is to investigate the photocatalytic degradation of propyl paraben (propyl para-hydroxybenzoate, PrP) using CuO-ZnO-NPs photocatalyst followed by the identification of the oxidation by-products. The CuO-ZnO-NPs material, synthesized using a green chemistry approach, was used as a photocatalyst for the removal of PrP. The nanoparticles were characterized by XRD, XRF, diffuse reflectance spectroscopy, ATG/DTG, FTIR, SEM-EDX, BET and FRX techniques.
View Article and Find Full Text PDFBiol Trace Elem Res
January 2025
College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.
Exposure to vanadium (V) occurs through the ingestion of contaminated water, polluted soil, V-containing foods and medications, and the toxicity and absorption during the small intestine phase after oral ingestion play crucial roles in the ultimate health hazards posed by V. In this study, the human colon adenocarcinoma (Caco-2) cells were selected as an intestinal absorption model to investigate the uptake and cytotoxicity of vanadyl sulfate (VOSO) and sodium orthovanadate (NaVO). Our results confirmed the cytotoxic effects of V(IV) and V(V) and revealed a greater toxicity of V(IV) than V(V) towards Caco-2 cells.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Floriculture, Ornamental Horticulture and Garden Design, Faculty of Agriculture (El-Shatby), Alexandria University, Alexandria, 21545, Egypt.
Natural extracts as biostimulants have the potential to enhance the productivity and growth of many medicinal and aromatic plants. This study aimed to enhance the growth, and essential oil (EO) content, as well as composition of Lavandula latifolia Medik. by using Malva parviflora L.
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