MoO₂/SiC Gradient Aerogel-Based Phase-Change Materials for Coordinating Efficient Solar Thermal Energy Conversion and Storage

Solar thermal energy conversion and storage represent a promising avenue for utilizing solar energy due to their high energy efficiency and ability to overcome solar radiation intermittency. However, constructing a high-performance solar heat storage material by coordinating photothermal conversion and phase-change material remains a considerable challenge. Herein, MoO₂ nanosheets are gradientally grown in a SiC nanowire aerogel via the chemical vapor deposition method to prepare a MoO₂/SiC gradient aerogel, in which stearic acid is impregnated to obtain aerogel-based phase-change composites. The composites demonstrate excellent photothermal conversion performance, ultrahigh heat storage capacity (latent heat retention of 97%), and enhanced thermal conductivity. MoO₂ nanosheets on SiC nanowires contribute to photothermal conversion; moreover, the unique gradient structure facilitates the gradual absorption of solar light to increase solar energy utilization. The ultrahigh porosity of aerogels can encapsulate a large amount of phase-change material, which synchronously stores the heat energy from solar energy photothermal conversion. The three-dimensional net structure of the SiC aerogel can provide an efficient continuity through the heat conduction channel, which improves the thermal conductivity and heat storage rate. This work provides an effective strategy for developing novel solar heat storage materials with elaborate nanostructures.