SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3770-9
Intramolecular through-space charge-transfer (TSCT)-enabled thermally activated delayed fluorescence (TADF) emitters have shown exceptional potential for advancing organic light-emitting diode (OLED) technologies, owing to their efficient utilization of triplet excitons and optimized photophysical properties. To date, the intrinsic correlation among molecular geometries, intramolecular non-covalent interactions, and photophysical properties in TSCT-TADF emitters remains unconfirmed, and this study theoretically clarifies this critical correlation. Specifically, through integrating molecular engineering, screening strategies, first-principles calculations, energy decomposition analysis, and statistical modeling, we systematically investigated 24 experimentally reported TADF molecules, and 54 newly designed structures in both solution and thin-film environments. We establish a clear geometric criterion for high-efficiency TSCT-TADF emitters: donor-acceptor (D-A) dihedral angles below 25° and interfragment distances within 4 Å—conditions validated by both theoretical predictions and experimental evidence. Based on this insight, we designed two novel molecular libraries with benzene- or carbazole-derivative bridges, using O-bridged triphenylamine (DPXZ) as the donor and quinolino[3,2,1-de]acridine-5,9-dione (QAO) as the acceptor. Our calculations confirm that sub-25° D-A dihedral angles correlate with exceptional delayed fluorescence efficiency, with predictions reaching up to 96% and an average of 70% for the new thin film systems. This study provides a rational design strategy for high-performance TSCT-TADF emitters, significantly advancing the molecular-level understanding of through-space interactions and accelerating the discovery of tailored, efficient OLED materials.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3739-8
The premature decay of electrochemical nitrogen reduction reaction (eNRR) performance at low electrode potentials remains a major obstacle to practical applications, primarily due to competition from the hydrogen evolution reaction (HER). A new paradigm capable of transcending current selectivity constraints is urgently required to advance eNRR toward industrial implementation. In this work, we propose two practical selectivity descriptors (ΔΔG and ΔU) based on a systematic investigation of the potential-dependent competition between eNRR and HER on confined dual-atom catalysts. The descriptor ΔΔG (ΔG_N2 − ΔG_H) identifies the potential range where N2 adsorption dominates over H adsorption, while ΔU (U_cross – U_eNRR) specifies the potential range to trigger direct eNRR, offering a quantitative benchmark for rational catalyst design. Ideal catalysts should maintain N2-preferential adsorption across a broad potential window to facilitate direct eNRR. Guided by this insight, we demonstrate that confined dual-atom configurations with optimized interatomic distances can simultaneously achieve both overwhelming N2 adsorption and sufficient activation, thereby overcoming conventional selectivity limitations. This strategy enables ammonia synthesis with industrially relevant production rates and current density even at elevated potentials. Our mechanistic insights not only elucidate the root causes of performance limitations in eNRR but also offer a rational design framework for developing high-performance catalysts across a broad range of electrochemical transformations.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3880-8
Formaldehyde oxidation reaction (FOR) demonstrates significant potential in energy conversion and chemical synthesis, yet developing catalysts for efficient operation at high current densities remains a challenge. Herein, we fabricated a Cu/Cu2O heterostructure nanowire catalyst on copper foam (Cu/Cu2O@CF) via interface engineering and investigated its FOR performance. Electrochemical tests show that Cu/Cu2O@CF exhibits excellent activity: it achieves 100 mA cm−2 at an ultra-low potential of −0.05 V (vs. RHE), outperforming most reported catalysts. Notably, this catalyst overcomes the deactivation limitation of conventional Cu-based catalysts above 0.5 V, maintaining a current density of 735 mA cm−2 at 0.6 V with excellent stability during long-term electrolysis. SCN−-induced Cu0 poisoning experiments confirm that Cu/Cu2O@CF retains a Cu/Cu2O mixed structure at 0.6 V, where Cu0-Cu+ synergy dominates its high activity. Density functional theory (DFT) calculations reveal two key advantages of this structure: it weakens OH− adsorption to avoid active site occupation, and reduces C–H bond cleavage barriers while promoting H* combination into H2. Product analysis shows Faradaic efficiencies for formate and H2 production are both ~100%. When coupled with the hydrogen evolution reaction (HER), the system's hydrogen production energy consumption is as low as 0.57 kWh m−3 H2, much lower than traditional water electrolysis. This work elucidates the regulatory mechanism of interface engineering on the FOR performance of Cu-based catalysts, expands the application of Cu-based heterostructures in high-current FOR, and guides the development of industrial-grade electrocatalysts.