Fabrication of a large-scale, high-performance, high stability cylinder freestanding rotating triboelectric nanogenerator (FR-TENG) for mechanical -energy -driven CO 2 reduction is a bottleneck to be overcome. Herein, from the reasonable geometric structure and triboelectric materials, a cylinder -type, large -area, high -stability, and soft -contact FR-TENG with superior output performance was well -constructed. At the optimal conditions, the maximum short-circuit current of FR-TENG is 35.1 mu A, the maximum transferred triboelectric charge is 350 nC, and the conversion efficiency from mechanical to electrical energy is up to 16.7 %, which outperforms previously reported results under similar conditions. Applying it into triboelectric plasma reduction of CO 2 system, the evolution rates of CO and O 2 are 8.50 and 4.33 mu mol h -1 , respectively, and the conversion efficiency from mechanical to chemical energy is 1.84 %, which is better than most of the previous benchmark results in TENG driven-CO 2 reduction systems. Finally, this device is applied to field experiments, and the generation rates of CO and O 2 are obtained to be 5.06 and 2.33 mu mol h -1 at a wind speed of 2.3 m s - 1 , respectively, with a maximum energy conversion efficiency of 0.72 %. This work provides a promising strategy for CO 2 reduction systems driven by mechanical energy.

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.

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 mmol 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.

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.

The simultaneous activation of surface lattice oxygen and dioxygen is key to transition metal oxide-based catalytic CO oxidation systems. However, the reaction is difficult at room temperature owing to the high metal-oxygen bond energy. This study presents a triboelectric plasma-transition metal oxide catalytic system driven by a triboelectric nanogenerator, which realizes CO oxidation reaction at room temperature and atmospheric pressure. Among the transition metal oxides evaluated, MnO2 nanostructures exhibited an optimal CO oxidation activity of 0.24 mmol.g(-1).h(-1) and a low energy consumption converted per mole CO of 6.0 x 10(3) kJ. For the activation of both surface lattice oxygen and dioxygen, multiple reaction pathways with barriers ranging from 0.37 to 2.43 eV have been revealed by X-ray photoelectron spectroscopy, electron paramagnetic resonance, and density functional theory simulation. These catalytic reaction phenomena have been explained by an extended Mars-van Krevelen mechanism, in which multiple pathways with various barriers were overcome by the electrons in the plasma with a uniform and broad distribution probability. This work provides an efficient strategy for the conversion and utilization of mechanical energy for chemical synthesis.

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.

CO2 conversion into high value-added chemicals and fuels has received considerable attention. However, the direct decomposition of CO2 using mechanical energy, which is an important renewable energy, remains challenging. This study realized triboelectric plasma decomposition of CO2 into CO with near 100% selectivity under normal temperature and pressure, which could be directly driven by mechanical energy. CO2- reactive species were detected by electron paramagnetic resonance spectra, verifying the existence of electron attachment dissociation (EAD) process of CO2 with a lower dissociation barrier. Average electron energy in the triboelectric plasma was decreased by modulating the distance and the polarity; thus, EAD proportion in the CO2 decomposition was increased, and a maximum CO evaluation rate of 2.2 mu mol h(-1) and an energy efficiency of 5.2% from plasma to chemical energy were achieved. This work provides a promising strategy for CO2 decomposition using 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.

Measuring the voltage, including open-circuit voltage (V-oc) and output voltage, is of great importance for evaluating the performances of a triboelectric nanogenerator (TENG). However, since one electrode of TENG is connected to the ground in the traditional measurement methods, the charges in this electrode are transferred to the ground, causing the underestimated voltage values. To solve this problem and measure the actual voltage, the non-grounded measurement configuration has been proposed here, in which both electrodes of the TENG are disconnected with the ground. From the measurement results of V-oc and output voltage by three non-grounded methods, it is obtained that the voltage ratio of non-grounded methods to traditional grounded methods are about 2.0 and 1.5 for sliding type and vertical type TENGs, respectively. The finite element simulation results for TENGs with three different modes match well with the measurement results. Furthermore, it is simulated that the voltage ratio of non-grounded to grounded methods is dependent on the parameters of the TENGs, such as the size of electrodes and the separation distance between them. Also, the non-grounded method has been applied in the TENG-induced micro -plasma to demonstrate its ability to measure the actual output voltage. The nongrounded measurement methods proposed here can measure the actual voltage of TENGs, which are of great significance to accurately evaluating the performances of TENGs.