Scalable Biomass-Derived Hydrogels for Sustainable Carbon Dioxide Capture

Carbon capture and sequestration are promising emissions mitigation technologies to counteract ongoing climate change. The aqueous amine scrubbing process is industrially mature but suffers from low energy efficiency and inferior stability. Solid sorbent-based carbon capture systems present a potentially advantageous alternative. However, practical implementation remains challenging due to limited CO₂ uptake at dilute concentrations and difficulty in regeneration. Here, we develop sustainable carbon-capture hydrogels (SCCH) with an excellent CO₂ uptake of 3.6 mmol g^-1 (400 ppm) at room temperature. The biomass gel network consists of konjac glucomannan and hydroxypropyl cellulose, facilitating hierarchically porous structures for active CO₂ transport and capture. Precaptured moisture significantly enhances CO₂ binding by forming water molecule-stabilized zwitterions to improve the amine utilization efficiency. The thermoresponsive SCCH exhibits a notable advantage of low regeneration temperature at 60 °C, enabling solar-powered regeneration and highlighting the potential for sustainable carbon capture to meet global decarbonization targets.