In-situ growth of Ni, Co-Prussian blue nanocubes on molten salt etched lamellar Ti3C2Tx/Ni for enhanced hybrid capacitive deionization.

A Ti 3 C 2 T x /Ni/NiCo-PBA composite is synthesized by in-situ growing NiCo Prussian blue (PB) nanocubes on Ti 3 C 2 T x /Ni sheets, serving as an electrode for hybrid capacitive deionization. Owing to the synergistic effect of Ti 3 C 2 T x , Ni nanoparticles, and NiCo-PBA, Ti 3 C 2 T x /Ni/NiCo-PBA demonstrates excellent desalination performance. Additionally, the desalination mechanism of Ti 3 C 2 T x /Ni/NiCo-PBA is thoroughly investigated. [Display omitted] • A Ti 3 C 2 T x /Ni/NiCo-PBA composite is synthesized by growing NiCo-PBA on Ti 3 C 2 T x /Ni sheets. • The AC||Ti 3 C 2 T x /Ni/NiCo-PBA HCDI device exhibits excellent desalination performance. • The desalination mechanism of Ti 3 C 2 T x /Ni/NiCo-PBA electrode is thoroughly investigated. The design and development of high-performance electrode materials are crucial for improving the desalination efficiency of hybrid capacitive deionization (HCDI). In this study, a Ti 3 C 2 T x /Ni/NiCo-PBA composite is synthesized by in-situ growing NiCo Prussian blue (PB) nanocubes on Ti 3 C 2 T x /Ni sheets, serving as an electrode for HCDI. The Ti 3 C 2 T x sheets provide excellent conductivity and a suitable substrate for the growth of NiCo-PBA nanocubes. The Ni nanoparticles help prevent the oxidation of Ti 3 C 2 T x sheets, and provide a source of Ni for NiCo-PBA synthesis. Additionally, the NiCo-PBA nanocubes effectively inhibit re-stacking of Ti 3 C 2 T x sheets, enlarge crystal lattice spacing, and facilitate diffusion and storage of salt ions. Consequently, the AC||Ti 3 C 2 T x /Ni/NiCo-PBA HCDI device exhibits a high salt removal capacity of 36.62 mg g−1, low energy consumption of 11.14 Wh m−3, and water recovery of 61.86 %. Importantly, the AC||Ti 3 C 2 T x /Ni/NiCo-PBA device achieves a good salt removal capacity of 53.22 mg g−1 in a high concentration NaCl solution (2000 μS cm−1). After 20 cycles, the desalination capacity remains stable, and the structure of Ti 3 C 2 T x /Ni/NiCo-PBA is intact, indicating excellent cycling stability. Additionally, the desalination mechanism of Ti 3 C 2 T x /Ni/NiCo-PBA electrode is thoroughly investigated. [ABSTRACT FROM AUTHOR]