A quantitative description of recombination processes in nanostructured semiconductor photocatalysts-one that distinguishes between bulk (charge transport) and surface (chemical reaction) losses-is critical for advancing solar-to-fuel technologies. Here we present an in situ experimental framework that determines the bias-dependent quantum yield for ultrafast carrier transport to the reactive interface. This is achieved by simultaneously measuring the electrical characteristics and the subpicosecond charge dynamics of a heterostructured photoanode in a working photoelectrochemical cell. Together with direct measurements of the overall incident-photon-to-current efficiency, we illustrate how subtle structural modifications that are not perceivable by conventional X-ray diffraction can drastically affect the overall photocatalytic quantum yield. We reveal how charge carrier recombination losses occurring on ultrafast time scales can limit the overall efficiency even in nanostructures with dimensions smaller than the minority carrier diffusion length. This is particularly true for materials with high carrier concentration, where losses as high as 37% are observed. Our methodology provides a means of evaluating the efficacy of multifunctional designs where high overall efficiency is achieved by maximizing surface transport yield to near unity and utilizing surface layers with enhanced activity.
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http://dx.doi.org/10.1021/nl504035j | DOI Listing |
ACS Appl Mater Interfaces
January 2025
School of Materials Science & Engineering, The Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China, Tianjin University, Tianjin 300072, China.
Rib fracture-related infection is a challenging complication of thoracic trauma due to the difficulty of treating it with antibiotics alone and the need for a second operation to remove the infected fixator and sterilize the surrounding infected tissue. In this study, inspired by the photocatalytic performance of and ion release from silver-based materials, including AgPO and AgS, a hybrid AgPO-AgS heterojunction was prepared based on anion exchange and a one-step calcination process to design a nonantibiotic coating aimed at preventing and treating rib fracture-related infection with short-term 808 nm near-infrared irradiation. Calcination at 250 °C enhanced the inductive effect of the phosphate radical and led to the formation of a tight nanoheterogeneous interface between AgPO and AgS, thereby promoting interfacial electron transfer and reducing the recombination of photogenerated carriers.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Columbia University, Department of Physics, New York, New York, USA.
A combined experimental and theoretical study is carried out on the three-body recombination process in a gas of microwave-shielded polar molecules. For ground-state polar molecules dressed with a strong microwave field, field-linked bound states can appear in the intermolecular potential. We model three-body recombination into such bound states using classical trajectory calculations.
View Article and Find Full Text PDFmSystems
January 2025
Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland.
Average nucleotide identity (ANI) is a widely used metric to estimate genetic relatedness, especially in microbial species delineation. While ANI calculation has been well optimized for bacteria and closely related viral genomes, accurate estimation of ANI below 80%, particularly in large reference data sets, has been challenging due to a lack of accurate and scalable methods. To bridge this gap, we introduce MANIAC, an efficient computational pipeline optimized for estimating ANI and alignment fraction (AF) in viral genomes with divergence around ANI of 70%.
View Article and Find Full Text PDFFront Immunol
January 2025
Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, China.
Background: Shell and pearl formation in bivalves is a sophisticated biomineralization process that encompasses immunological and mineralization aspects, particularly during shell repair and the initial stages of pearl cultivation when a nucleus is inserted. Here, we describe a novel C-type lectin, HcLec1, isolated and characterized from the freshwater pearl mussel Lea.
Methods: Immune challenge, RNA interference (RNAi) experiments, ELISA, and antibacterial assays were employed to investigate the role of HcLec1 in innate immunity.
Biochem J
January 2025
The Sun Yat-Sen University, Guangzhou, China.
The N6-methyladenine (6mA) modification is an essential epigenetic marker and plays a crucial role in processes, such as DNA repair, replication, gene expression regulation, etc. YerA from Bacillus subtilis is considered a novel class of enzymes capable of catalyzing the deamination of 6mA to produce hypoxanthine. Despite the significance of this type of enzymes in bacterial self-defense systems and potential applications as a gene-editing tool, the substrate specificity, the catalytic mechanism and the physiological function of YerA are currently unclear due to the lack of structural information.
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