Gangqiang Zhu

Nitrogen fixation is vital for ecological balance and agricultural production, whereas the classic Haber–Bosch synthetic ammonia route is energy-intensive and environmentally detrimental. Mechanical energy is ubiquitous in nature, making its utilization for nitrogen fixation highly attractive. Flexoelectric materials can convert mechanical energy to electric energy under the excitation of mechanical strain gradients, yielding the novel catalysis technology flexocatalysis. Flexocatalysis can occur almost in all catalysts. In this work, nano-CeO2 with abundant oxygen vacancies are used as a flexocatalyst realized direct nitrogen fixation from air under vibration. The maximum NH4+ production rate reaches 181.24 μmol g–1 h–1, which is 17.9 times that of the catalyst-free control. Density functional theory (DFT) analysis confirms that in-plane anisotropy-induced lattice distortion provides direct evidence for the flexoelectricity of CeO2. This work holds potential value for future applications of ambient mechanical vibration energy in flexocatalysis for direct nitrogen fixation from air.

Solid–liquid triboelectrification provides a direct route for converting interfacial mechanical motion into electrochemical activity, yet its coupling with hydrodynamic regulation at polymer/water interfaces remains insufficiently understood. Here, we report an interface-engineered tribocatalytic tube based on rotational solid–liquid triboelectrification at a fluorinated ethylene propylene (FEP)/water interface for pollutant decomposition without additional micro/nano-catalysts. In this system, a sealed cylindrical reactor lined with FEP is rotated to impose repetitive contact, friction, and separation between the liquid phase and the dielectric surface, thereby enabling interfacial charge separation and reactive oxygen species generation. Under optimized conditions, the system achieves decomposition ratios of 82.1% for rhodamine B (RhB), 50.4% for methylene blue (MB), 17.8% for tetracycline (TC), and 12.5% for methyl orange (MO) within 60 min. A total organic carbon (TOC) removal of 49.7% is obtained for RhB, indicating partial mineralization and the formation of oxidized intermediates. Key experimental parameters, including rotating speed, pH, and tube material, are systematically discussed. Radical quenching, electron paramagnetic resonance, and fluorescence-probe experiments reveal that •O2– and •OH play dominant roles in the decomposition process. This work establishes a material-interface route for converting low-frequency mechanical energy into interfacial redox activity and provides a design concept for mechanical-energy-driven pollutant decomposition.

Photothermal CO2 methanation offers a promising strategy for carbon-neutral fuel production. However, simultaneously achieving high activity, selectivity, and long-term stability at low temperatures remains challenging due to inherent trade-offs in reaction kinetics and competing pathways. Herein, we report a photothermal Ru/MnO catalyst featuring well-defined Ru–O–Mn(II) interfacial junctions, where Ru sites drive H2 dissociation, while the interface enhances CO2 adsorption, enabling efficient cleavage of HCOO* intermediates for further methanation at low temperatures. Under photothermal conditions, the optimized Ru/MnO-3 catalyst achieves a CH4 productivity of 64.79 mmol·g–1·h–1 with 31.5% CO2 conversion at 175 °C, significantly outperforming its thermally driven counterpart. In situ Fourier-transform infrared (FTIR) spectroscopy combined with density functional theory (DFT) calculations reveals temperature-dependent reaction behavior: at low temperatures, photothermal excitation lowers the kinetic barrier for formate transformation through enhanced hydrogen activation, whereas at elevated temperatures, the reaction increasingly favors CO*-involving pathways dominated by thermal effects. This photothermally induced modulation of reaction pathways, together with enhanced CO2 adsorption at Ru–O–Mn(II) interfaces and efficient H2 activation, underpins the observed low-temperature performance. Our findings provide mechanistic insights into photothermal CO2 methanation and highlight interfacial engineering as an effective strategy for designing low-temperature photothermal catalysts.

Plasmonic metal–semiconductor heterostructures are widely studied for light-harvesting applications, yet the role of localized surface plasmon resonance (LSPR) in carrier extraction on the semiconductor side remains poorly understood. Here, we show that engineering the dielectric environment in Au/CeO2 using ultrathin nanoporous Ceria transforms plasmonically activated volume (PAV) on CeO2 side from interface-confined plasmonic excitation into a spatially extended, volume-activated process. meV-resolution electron energy-loss spectroscopy visualizes LSPR propagation throughout the porous framework, while photoluminescence spectroscopy reveals an enhanced contribution from fast charge-transfer channels. Quantitative analysis establishes the correlation among the PAV, fast charge transfer, and carrier utilization efficiency. These findings highlight the importance of semiconductor-side carrier dynamics in plasmonic heterostructures and establish dielectric-environment engineering as an effective strategy for extending plasmonic functionality beyond the immediate metal–semiconductor interface.

Hydrogen peroxide (H₂O₂) is an essential industrial oxidant, yet its conventional production remains energy-intensive and generates hazardous byproducts. Flexocatalysis has emerged as a promising mechanochemical strategy that overcomes the symmetry constraints of piezoelectric materials, allowing a wider range of semiconductors to participate in mechano-driven redox reactions. However, this green approach faces challenges due to inefficient mechanochemical energy conversion and insufficient active sites. In this study, the g-C₃N₄/SrTiO₃ nanocomposites are prepared by initially hydrothermally-synthesizing SrTiO₃, which was then mechanically mixed with g-C₃N₄ and calcined. The optimized heterojunction demonstrates an elevated H₂O₂ production rate of 645.1 μmol·g^-1·h^-1 when subjected to ultrasonication, outperforming the yields of pristine g-C₃N₄ and SrTiO₃ by 2.7 and 3.7 folds, respectively. The improved efficiency is attributed to the effective spatial separation of mechano-induced charges across the heterointerface, which suppresses charge recombination and thereby enhances the overall redox efficiency. Mechanistic investigations, including electron spin resonance spectroscopy and radical trapping experiments, collectively demonstrate that the sequential two-step single-electron oxygen reduction serves as the predominant pathway for H₂O₂ generation. This study highlights the potential of heterojunction engineering in advancing flexocatalytic systems and presents a scalable, sustainable strategy for ultrasound-driven H₂O₂ synthesis.

A highly efficient pyro-catalytic system based on a g-C₃N₄/ZnO composite has been developed for dye degradation under near-room-temperature thermal cycling (25–60 °C). This system integrates pyroelectric charge generation with electrochemical redox reactions. The g-C₃N₄/ZnO for pyro-catalytic Rhodamine B (RhB) dye decomposition with 95.6% efficiency in the dark, whereas pristine g-C₃N₄ reached only approximately 60.1% under identical conditions. The degradation mechanism is primarily driven by the in situ generation of superoxide (•O₂⁻) and hydroxyl (•OH) radicals, as verified by radical quenching experiments. The formation of the composite facilitates the efficient spatial separation of pyroelectric-induced charges, thereby endowing g-C₃N₄/ZnO with a significantly enhanced pyro-catalytic performance compared to g-C₃N₄ alone. This study demonstrates the promising application of g-C₃N₄/ZnO as a high-performance pyro-catalyst under mild thermal conditions, offering a sustainable and light-independent strategy for wastewater treatment by utilizing ambient temperature fluctuations.

This review comprehensively concludes these strategies to enhance the pyrocatalysis, including increasing polarization strength, modulating microstructure, optimizing surface and interface regulation and building the multicatalytic synergy.