N2 fixation driven by mechanical energy is a promising strategy for production of nitrogen-enriched compounds. However, the activity of mechanical-energy-driven N2 fixation is very low. Herein, a mechanical-energy-driven triboelectric plasma jet was constructed to achieve N2 fixation in air at room temperature and atmospheric pressure. Under optimal conditions, the NOX production rate of 4.82 μmol h−1 is 23-fold better than the previous record using a triboelectric nanogenerator. The electrical to chemical energy conversion efficiency and energy cost for NOX production are 4.92% and 1.76 MJ mol−1 N−1, respectively, and the energy cost is the best result in the reported plasma N2 fixation reaction at room temperature and atmospheric pressure. Because of the lower average energy of electrons in the triboelectric plasma jet, the vibrational excitation dissociation process with low energy barriers is the major mechanism for N2 fixation. This study provides an effective strategy for N2 fixation using mechanical energy.

As the single electron transfer of CO2 to CO2- ions is the critical step in the CO2 activation, it is very important to develop appropriate strategies to construct efficient catalytic systems. Herein, we constructed a coupled catalytic system consisting of mechanical-energy-driven triboelectric plasma and indium oxide rich in oxygen vacancies to achieve CO2 reduction to CO at room temperature and atmospheric pressure. At the discharge distance of 0.6 mm, the indium oxide with more oxygen vacancies exhibited an optimal catalytic activity of 0.20 mmolg(-1)h(-1) for CO evolution rate, and the conversion efficiency from electrical to chemical energy was 10.8 %. Electron paramagnetic resonance experiments showed that a large amount of CO2- ions were generated in the triboelectric plasma. The introduction of oxygen vacancies could increase the density of states near the Fermi level of indium oxide catalysts, stabilize highly active CO2- ions, and reduce the energy barrier of CO2- decomposition.

The activities of semiconductor-based catalytic reactions are limited by mismatch between energy bandgaps of semiconductors and redox potentials of inert small molecules, especially for stable molecules, such as CO2. Herein, a triboelectric plasma catalytic system using metal oxide catalysts has been developed, which reduces CO2 to CO at room temperature and atmospheric pressure. Among the various metal oxide semiconductors, TiO2 catalyst exhibited the best activity, reaching a production rate of 0.14mmol(.)gcat(1.)h (1), and an energy efficiency of 5.3 % for the conversion of electrical to chemical energy. In triboelectric plasma, CO2 molecules were pre-activated to form the transient CO2 anions, and the limiting step of electron transfer between TiO2 and CO2 was avoided, overcoming the energy mismatch between catalyst and CO2. The energy barrier of CO2 dissociation was markedly reduced to 0.18 eV. This work provides an effective strategy to overcome the energy bandgap restriction inherent in semiconductor-based catalytic reactions. (c) 2023 Elsevier Inc. All rights reserved.

Acetone is widely used as a solvent in industry, which is volatile and harmful to the environment and people’ health. Hence, it is very important for real‐time detection of acetone concentration in exhaust gas or the surrounding air. Herein, a self‐powered acetone gas‐sensing system (SASS) based on passive half‐wave rectification power management circuits (HW‐PMCs), enhanced pulsed triboelectric nanogenerator (pulsed‐TENG), and Co 3 O 4 acetone gas sensor is reported. First, HW‐PMC is developed based on the half‐wave rectifier with 470 μF capacitor and limited capacitor voltage (<5.5 V) to store energy efficiently. Results demonstrate that simulated energy storage efficiency of HW‐PMC is 42.2% and is 26.3 times higher than that of conventional PMCs. Then, the external capacitor is connected to electrodes of pulsed‐TENG, which forms enhanced pulsed‐TENG. The highest energy storage efficiency of HW‐PMC can reach 25.8% using enhanced pulsed‐TENG. The calculator is successfully powered using enhanced pulsed‐TENG and HW‐PMC. Finally, according to the characteristics of HW‐PMC, enhanced pulsed‐TENG, and Co 3 O 4 gas sensor, SASS is developed and can detect 2 ppm of acetone at room temperature. SASS is important to environmental protection and reduction of production cost.

Mechanical energy‐induced CO 2 reduction is a promising strategy for reducing greenhouse gas emissions and simultaneously harvesting mechanical energy. Unfortunately, the low energy conversion efficiency is still an open challenge. Here, multiple‐pulse, flow‐type triboelectric plasma with dual functions of harvesting mechanical energy and driving chemical reactions is introduced to efficiently reduce CO 2 . CO selectivity of 92.4% is achieved under normal temperature and pressure, and the CO and O 2 evolution rates reach 12.4 and 6.7 µmol h −1 , respectively. The maximum energy conversion efficiencies of 2.3% from mechanical to chemical energy and 31.9% from electrical to chemical energy are reached. The low average electron energy in triboelectric plasma and vibrational excitation dissociation of CO 2 with low barrier is revealed by optical emission spectra and plasma simulations, which enable the high energy conversion efficiency. The approach of triboelectric plasma reduction reported here provides a promising strategy for efficient utilization of renewable and dispersed mechanical energy.

Oxidation reactions play a critical role in processes involving energy utilization, chemical conversion, and pollutant elimination. However, due to its spin-forbidden nature, the reaction of molecular dioxygen (O2) with a substrate is difficult under mild conditions. Herein, we describe a system that activates O2 via the direct modulation of its spin state by mechanical energy-induced triboelectric corona plasma, enabling the CO oxidation reaction under normal temperature and pressure. Under optimized reaction conditions, the activity was 7.2 μmol h−1, and the energy consumption per mole CO was 4.2 MJ. The results of kinetic isotope effect, colorimetry, and density functional theory calculation studies demonstrated that electrons generated in the triboelectric plasma were directly injected into the antibonding orbital of O2 to form highly reactive negative ions O2−, which effectively promoted the rate-limiting step of O2 dissociation. The barrier of the reaction of O2− ions and CO molecular was 3.4 eV lower than that of O2 and CO molecular. This work provides an effective strategy for using renewable and green mechanical energy to realize spin-forbidden reactions of small molecules.