Plasmonic group 4 transition metal carbide interfaces for solar‐driven desalination

Abstract

To combat the dwindling supply of freshwater, solar‐driven desalination using plasmonic nanomaterials has emerged as a promising and renewable solution. Refractory plasmonic carbide nanomaterials are exciting candidates that are inexpensive and chemically robust but have not been widely explored. Herein, plasmonic carbide interfaces made of TiC, ZrC, and HfC nanoparticle aggregates loaded onto to a mixed cellulose ester (MCE) membrane were explored to gain insight into their solar‐vapor generation and desalination potential. Desalination using Atlantic Ocean water under 1 sun intensity yielded rates of 1.26 ± 0.01, 1.18 ± 0.02, and 1.40 ± 0.01 kg m−2 h−1, with efficiencies of 86%, 80%, and 96% for TiC, ZrC, and HfC, respectively. Carbide interfaces showed good stability and effectively removed heavy metal ions and salt from solutions with concentrations up to 35%. PVA hydrogel based TMC evaporators afforded rates of 3.31 ± 0.03 and 3.22 ± 0.03 kg m−2 h−1 for TiC and ZrC, respectively. The HfC‐PVA interface afforded a high solar desalination rate of 3.69 ± 0.04 kg m−2 h−1, corresponding to an efficiency of 97% under 1‐sun illumination. The hydrogel evaporators also retained their strong salt rejection action over time.

Stability and Surface Functionalization of Plasmonic Group 4 Transition Metal Nitrides

“…The LSPR maximum of ZrN and TiN were significantly red shifted compared to the unfunctionalized NPs indicating potential hotspot formation due to cross-linking. 41 The long-term stability of these NPs suspended in ethanol was investigated over 60 days (Figure 6B). The LSPR of TiN, ZrN, and HfN red-shifted by 9, 15, and 19 nm, respectively, over the course of 60 days indicating good oxidative stability.…”