Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202511090
In ecological restoration projects such as wetland reconstruction and mine reclamation, seedling transplantation or mechanical damage often leads to slow healing, reducing survival rates and weakening carbon sequestration and soil-water conservation functions. To address secondary pollution from traditional chemical remediation, this study developed a self-powered piezoelectric hydrogel for green electrical stimulation of plant wounds. The hydrogel, based on polyacrylamide/polyethylene glycol (PAM/PEG) with CaCl2, formed a microporous, locally ordered piezoionic network. Characterization included microstructure, piezoionic response, and water retention. At 30 °C and 55% relative humidity, the hydrogel retained about 70% mass after 80 h of continuous water loss. Under simulated environmental mechanical forces, the hydrogel generated a peak voltage of approximately 6 mV. In tomato seedling stem models, wound callus area ratios reached approximately 49.50%, 64.87%, and 86.13% at 3, 5, and 10 days, respectively, when the hydrogel was attached and driven by environmental forces. The PAM/PEG/CaCl2 hydrogel efficiently converts environmental mechanical energy into mild electrical signals, promoting plant wound healing, reducing exogenous chemical use, and offering a low-carbon, environmentally friendly material pathway for ecological restoration and urban green space management.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3366-9
Organic solar cells (OSCs) have transitioned from <1% initial power conversion efficiency (PCE) to a benchmark exceeding 20% in single-junction and tandem architectures, marking a critical milestone for solution-processable photovoltaics. This review consolidates recent reports (2022–2025) on OSCs with PCE >20%, analyzing key strategies: photoactive material innovation (wide-bandgap polymer donors, narrow-bandgap non-fullerene acceptors), multi-component system construction, deposition protocol optimization, solid/solvent additive engineering, and hole/electron transport layer development. Empirical data from 15 high-impact studies reveal PCEs of 20.0–20.6% in single-junction devices and 20.2–26% in perovskite/organic tandem cells, with interfacial engineering (e.g., yttrium phosphotungstate, carbazole-modified 2PACz, naphthalene diimide interlayers) suppressing bimolecular recombination and enabling scalable large-area fabrication. Operational stability remains a bottleneck: amide-based cathode interlayers achieve 20% PCE with dual-modification mechanisms, while self-assembled monolayers enable hole transport layer-free devices with 18% efficiency and improved stability. The review identifies next-stage challenges: reducing voltage losses (to <0.5 V), scaling deposition uniformity beyond 100 cm², and achieving cost parity with silicon (<$0.30/Wp). These issues are critical for flexible and wearable power suppliers, where mechanical durability (<5% PCE degradation after 1000 bending cycles) and low-temperature processing (<150°C) are mandatory. The analysis provides a roadmap for industrial translation, emphasizing that material–device co-optimization, rather than isolated breakthroughs, will determine commercial viability.