Search

Carbon‐based materials have been utilized as effective catalysts for hydrogen peroxide electrosynthesis via two‐electron oxygen reduction reaction (2e ORR), however the insufficient selectivity and productivity still hindered the further industrial applications. In this work, we report the Fe−O4 motif activated graphitic carbon material which enabled highly selective H2O2 electrosynthesis operating at high current density with excellent anti‐poisoning property. In the bulk production test, the concentration of H2O2 cumulated to 8.6 % in 24 h and the corresponding production rate of 33.5 mol gcat−1 h−1 outperformed all previously reported materials. Theoretical model backed by in situ characterization verified α‐C surrounding the Fe−O4 motif as the actual reaction site in terms of thermodynamics and kinetics aspects. The strategy of activating carbon reaction site by metal center via oxo‐bridge provides inspiring insights for the rational design of carbon materials for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

High‐loading electrode is a prerequisite for achieving high energy density in industrial applications of lithium‐ion batteries. However, an increased loading leads to elevated battery polarization and reduced battery power density, which presents a significant technical bottleneck in the industry. The present study focuses on designing a rapid electrolyte diffusion pathway to diminish lithium concentration polarization for the high‐loading LiNi0.83Mn0.12Co0.05O2 (NMC83) electrode by employing two layers of NMC83 materials with different sizes. This innovative architecture demonstrates exceptional rate performance even under challenging conditions with high‐loading and high‐rate. Additionally, the interrelationships between electrode structure, process route, porosity, and optimal thickness ratio between layers are discussed, providing valuable guidance for industrial promotion and application. The designed L‐Dry‐S electrode structure (coating large particles first and then small particles) effectively mitigates concentration polarization in the thick electrode, which is attributed to the fast electrolyte diffusion channel and the differential reaction speeds of NMC83 particles with varying sizes. The knowledge from this work is broadly applicable to other material systems. [ABSTRACT FROM AUTHOR]

The development of the embryo sac is an important factor that affects seed setting in rice. Numerous genes associated with embryo sac (ES) development have been identified in plants; however, the function of the DEAD-box RNA helicase family genes is poorly known in rice. Here, we characterized a rice DEAD-box protein, RH52A, which is localized in the nucleus and cytoplasm and highly expressed in the floral organs. The knockout mutant rh52a displayed partial ES sterility, including degeneration of the ES (21%) and the presence of a double-female-gametophyte (DFG) structure (11.8%). The DFG developed from two functional megaspores near the chalazal end in one ovule, and 3.4% of DFGs were able to fertilize via the sac near the micropylar pole in rh52a. RH52A was found to interact with MFS1 and ZIP4, both of which play a role in homologous recombination in rice meiosis. RNA-sequencing identified 234 down-regulated differentially expressed genes associated with reproductive development, including two, MSP1 and HSA1b , required for female germline cell specification. Taken together, our study demonstrates that RH52A is essential for the development of the rice embryo sac and provides cytological details regarding the formation of DFGs. [ABSTRACT FROM AUTHOR]

Sustaining the steady state for highly active non‐stoichiometric iridium (Ir)‐based oxide (IrOx) at low Ir loading remains challenging primarily due to the continuous oxidation and sequent dissolution of Ir active sites during the oxygen evolution reaction (OER). In this context, a new iridium–cerium (Ce) substitution solid solution oxide (SSO) has been developed, featuring uniformly dispersed Ir atoms within Ce dioxide (CeO2) matrix as electron buffer, which delivers remarkable acidic OER catalytic activity and enhanced stability. The electron‐buffering capacity of CeO2 facilitates the charge transfer toward Ir atoms, leading to abundant active low‐valence Ir sites and effectively prevent their oxidation and dissolution. As a result, Ir─Ce SSO demonstrates an overpotential of merely 238 mV@10 mA cm−2. Proton exchange membrane water electrolyzer employing Ir─Ce SSO at a low Ir loading of 396 µgIr cm−2 operates consistently for over 100 h@500 mA cm−2. Density functional theory (DFT) calculations corroborate that the electron‐buffering effect of CeO2 enriches the density of IrIII and substantially increases the dissolution energy barrier of Ir atoms. This study presents a viable approach to addressing the issues of instability and low efficiency in Ir‐based OER electrocatalysts for acidic water electrolysis. [ABSTRACT FROM AUTHOR]

Refining synthesis strategies for metal–organic framework (MOF)-based catalysts to improve their performance and stability in an oxygen evolution reaction (OER) is a big challenge. In this study, a series of nanostructured electrocatalysts were synthesized through a solvothermal method by growing MOFs and metal–triazolates (METs) on nickel foam (NF) substrates (named MET-M/NF, M = Fe, Co, Cu), and these electrocatalysts could be used directly as OER self-supporting electrodes. Among these electrocatalysts, MET-Fe/NF exhibited the best OER performance, requiring only an overpotential of 122 mV at a current density of 10 mA cm−2 and showing remarkable stability over 15 h. The experimental results uncovered that MET-Fe/NF underwent an in situ structural reconstruction, resulting in the formation of numerous iron/nickel (oxy)hydroxides with high OER activity. Furthermore, in a two-electrode water-splitting setup, MET-Fe/NF only required 1.463 V to achieve a current density of 10 mA cm−2. Highlighting its potential for practical applications. This work provides insight into the design and development of efficient MOF-based OER catalysts. [ABSTRACT FROM AUTHOR]

Gene therapy involves altering of the genome of selected cells within a patient (1). Although CRISPR/Cas9 has received widespread attention because of the groundbreaking work done by Emmanuelle Charpentier and [...]

Cr3+‐doped phosphors are highly recognized in various fields for their remarkable luminous efficiency and spectral flexibility, including modern agriculture and horticulture. However, the shortage of suitable Cr3+‐doped phosphors for far‐red LED devices has inhibited their popularization in plant lighting. Herein, an innovative Cr3+‐doped phosphor Ca2YAl3Ge2O12:Cr3+ (CYAG:Cr3+), achieving a broad far‐red emission at 770 nm upon 450 nm blue light excitation is designed. The optimal CYAG:Cr3+ phosphor exhibits a high internal quantum yield of 78.2% and low thermal‐quenching behavior of 85%@373 K. Thus, the fabricated phosphor‐converted LEDs (pc‐LEDs) for plant far‐red lighting have a high output power of 33.3 mW and photovoltaic conversion efficiency of 11.5% at 100 mA. The potential of CYAG:Cr3+ in plant lighting is assessed by supplementing the far‐red lighting of Italian lettuce with fabricated pc‐LEDs, and the biomass of Italian lettuce is significantly increased by 33%. The successful development of CYAG:Cr3+ phosphors provides a high‐quality option for plant far‐red light devices and further stimulates the development of new Cr3+‐doped plant‐lighting phosphors. [ABSTRACT FROM AUTHOR]