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 similar to 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 (phi) 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.