The borophene quantum dots scaffolded TiO₂ nanocomposite as an efficient photo electrocatalyst for water splitting application

Herein, we are scaffolding borophene quantum dots (BPQDs) on photoactive semiconductor nanomaterial such as TiO₂ nanoparticle which shows enhanced photoelectrochemical (PEC) water splitting activity. The BPQDs are synthesized by sonochemical method and then scaffolded onto TiO₂ nanoparticles by hydrothermal method. Further, the concentration of BPQDs on TiO₂ nanoparticles is optimized for better photoelectrochemical water splitting application. The effective absorption edge is found to be less (2.51 eV) for 2.5 wt% BPQDs scaffolded TiO₂ nanoparticles as studied by UV–Visible spectroscopic analysis. Transmission electron microscopic (TEM) images reveal the scaffolding of BPQDs of size (2–9) nm with TiO₂ nanoparticles of having the size ∼25 nm. XRD results confirmed the anatase phase of TiO₂ nanoparticles and b-rhombohedral boron structure for BPQDs. The FTIR and XPS results confirms the presence of boron functionalized groups in the nanocomposites. The photoluminescence (PL) spectroscopic results revealed the decrease in PL emission intensity for BPQDs/TiO₂ nanocomposite indicating the decreased photogenerated charge carriers recombination time. The work function (ϕ) is found to be less for BPQDs/TiO₂ nanocomposite signifying the easy release of electrons under the presence of visible light illumination. Further, BPQDs/TiO₂ nanocomposite shows the improvement in photoelectrochemical (PEC) water splitting due to the synergistic effects of individual components.