Efficient Light to Heat Conversion in Sb₂Se₃ Nanorods and the Role of Macro-channel Imprinted Sb₂Se₃ Loaded Hybrid Membrane for Superior Desalination Performance

This report validates Sb₂Se₃ nanorods (NRs) as a potential contender for solar thermal heat generation. The water droplet experiment shows Sb₂Se₃'s light-to-heat conversion efficiency as ≈57.8% for red (671 nm), 58% for green (532 nm) lasers. Following this PVDF(M)/ Sb₂Se₃ NRs hybrid membranes for solar desalination reached ≈59°C in 15 minutes of illumination. The heat generation is dominated by an electron/hole-acoustic phonon scattering mechanism. Despite having superior visNIR absorption and heat localization in Sb₂Se₃ NRs, the hybrid membranes show an evaporation rate of 1.72 kg m^-2 h^-1 only, even if mass loading is increased. The hydrophobic Sb₂Se₃ NRs layer restricts water diffusion to hot zones, reducing solar evaporation efficiency. A novel macro channel imprinting strategy in hybrid membranes speeds up water transport to the hot zone. Consequently, optimized macro channel membranes achieve ≈2.37 kg m^-2 h^-1 mass loss and 148% solar evaporation efficiency under a 1000 W m^-2 mercury vapor lamp. Therefore, imprinting macro-channel can be a possible strategy, addressing the hydrophobic materials in desalination applications which can be expanded in other similar materials. Moreover, its outdoor sunlight application achieves impressive solar evaporation efficiency (≈108%). The steam generated effectively removes heavy metals, meeting World Health Organization (WHO) potable water standards.