Electrocatalytic Reduction of Carbon Dioxide on Nanosized Fluorine Doped Tin Oxide in the Solution of Extremely Low Supporting Electrolyte Concentration: Low Reduction Potentials

Fluorine doped tin oxide (FTO) has been prepared via the direct chemical reaction of tin oxide powders and hydrofluoric acid at room temperature. The image of FTO displays a sphere-like structure with an average diameter of 40–100 nm. The spectra of X-ray photoelectron spectroscopy (XPS) demonstrate that fluorine is doped into SnO₂. A well-defined reduction peak at −0.50 V (vs SCE) is detected on the cyclic voltammogram (CV) of the nanosized FTO (n-FTO) electrode in CO₂-saturated 3.6 × 10^–4 μM H₂SO₄ solution of pH 5.5, which is strong evidence for the electrochemical reduction of CO₂. This result indicates that the n-FTO electrode in such an extremely low supporting electrolyte concentration exhibits good electrocatalytic ability toward CO₂ reduction under lower potentials. On the basis of reduction peak current as a function of scan rate, the reduction of CO₂ is first performed via adsorption of CO₂ on the n-FTO electrode surface, and then CO₂ is reduced. The product solution obtained under a constant potential of −0.90 V (vs Ag/AgCl with saturated KCl solution) is used for analysis of UV–vis spectra, ¹H NMR, and gas chromatography; the results demonstrate the presence of formic acid and methanol in the product solution, but formic acid is a main product. Faradaic efficiency for formic acid is 82.3%

Alternative splicing of the PECTINESTERASE gene encoding a cell wall-degrading enzyme affects postharvest softening in grape

The firmness of table grape berries is a crucial quality parameter. Despite extensive research on postharvest fruit softening, its precise molecular mechanisms remain elusive. To enhance our comprehension of the underlying molecular factors, we initially identified differentially expressed genes (DEGs) by comparing the transcriptomes of folic acid (FA)-treated and water-treated (CK) berries at different time points. We then analyzed the sequences to detect alternatively spliced (AS) genes associated with postharvest softening. A total of 2,559 DEGs were identified and categorized into four subclusters based on their expression patterns, with subcluster-4 genes exhibiting higher expression in the CK group compared with the FA treatment group. There were 1,045 AS-associated genes specific to FA-treated berries and 1,042 in the CK-treated berries, respectively. Gene Ontology (GO) annotation indicated that the AS-associated genes in CK-treated berries were predominantly enriched in cell wall metabolic processes, particularly cell wall degradation processes. Through a comparison between treatment-associated AS genes and subcluster-4 DEGs, we identified eight genes, including Pectinesterase 2 (VvPE2, Vitvi15g00704), which encodes a cell wall-degrading enzyme and was predicted to undergo an A3SS event. The reverse transcription polymerase chain reaction further confirmed the presence of a truncated transcript variant of VvPE2 in the FA-treated berries. Our study provides a comprehensive analysis of AS events in postharvest grape berries using transcriptome sequencing and underscores the pivotal role of VvPE2 during the postharvest storage of grape berries

Consecutive hybrid mechanism boosting Na+ storage performance of dual-confined SnSe2 in N, Se-doping double-walled hollow carbon spheres

Rationally designed hierarchical structures and heteroatomic doping of carbon are effective strategies to enhance the stability and electrical conductivity of materials. Herein, SnSe2 flakes were generated in the double-walled hollow carbon spheres (DWHCSs), in which N and Se atoms were doped in the carbon walls, to construct SnSe2@N, Se-DWHCSs by confined growth and in-situ derivatization. The N and Se-doped DWHCSs can effectively limit the size increase of SnSe2, promote ion diffusion kinetics, and buffer volume expansion, which can be proved by electron microscope observation and density functional theory calculation. Consequently, the SnSe2@N, Se-DWHCSs as an anode material for sodium ion batteries (SIBs) demonstrated a distinguished reversible capacity of 322.8 mAh g(-1) at 5 A g(-1) after 1000 cycles and a superior rate ability of 235.3 mAh g(-1) at an ultrahigh rate of 15 A g(-1). Furthermore, the structure evolution and electrochemical reaction processes of SnSe2@N, Se-DWHCSs in SIBs were analyzed by ex-situ methods, which confirmed the consecutive hybrid mechanism and the phase transition process. (C) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press.N