Synergy of photocatalysis and photothermal effect in integrated 0D perovskite oxide/2D MXene heterostructures for simultaneous water purification and solar steam generation

Inspired by the transpiration and natural photosynthesis of plants, bifunctional properties of mixed-dimensional Ti₃C₂T_x (MXene)/La_0.5Sr_0.5CoO₃ (LSC) nanohetero-structures to degrade pollutants via photochemical reactions and simultaneously produce fresh water through photothermal effect were explored. Zero-dimensional (0D) LSC in the nanohybrid can absorb short-wave photons to generate active oxidative species for photocatalytic degradation, while photothermal components can convert long-wave photons into heat to evaporate water. More importantly, the hybrid hydrogels are developed by integrating MXene/LSC nanohybrids with polyvinyl alcohol (PVA) and chitosan (CS), which offers excellent thermal insulation, fluent water transport and low water vaporization enthalpy to accelerate water evaporation. Benefiting from the materials selection and design, the assembled MXene/LSC hydrogels (MLH) achieve a light-to-heat conversion efficiency of 92.3 %, and acquire a superior photodegradation efficiency of 97.2 % toward the removal of tetracycline hydrochloride (TC). The MLH evaporator also possesses a significant capacity in the purification of brine and wastewater.