Abstract
While the CuBi2O4-based photocathode has emerged as an ideal candidate for photoelectrochemical water splitting, it is still far from its theoretical values due to poor charge carrier transport, poor electron–hole separation, and instability caused by self-photoelectric-corrosion with electrolytes. Establishing synthesis methods to produce a CuBi2O4 photocathode with sufficient cocatalyst sites would be highly beneficial for water splitting. Here, the platinum-enriched porous CuBi2O4 nanofiber (CuBi2O4/Pt) with uniform coverage and high surface area was prepared as a photocathode through an electrospinning and electrodeposition process for water splitting. The prepared photocathode material was composed of a CuBi2O4 nanofiber array, which has a freestanding porous structure, and the Pt nanoparticle is firmly embedded on the rough surface. The highly porous nanofiber structures allow the cocatalyst (Pt) better alignment on the surface of CuBi2O4, which can effectively suppress the electron–hole recombination at the electrolyte interface. The as-fabricated CuBi2O4 nanofiber has a tetragonal crystal structure, and its band gap was determined to be 1.8 eV. The self-supporting porous structure and electrocatalytic activity of Pt can effectively promote the separation of electron–hole pairs, thus obtaining high photocurrent density (0.21 mA/cm2 at 0.6 V vs. RHE) and incident photon-to-current conversion efficiency (IPCE, 4% at 380 nm). This work shows a new view for integrating an amount of Pt nanoparticles with CuBi2O4 nanofibers and demonstrates the synergistic effect of cocatalysts for future solar water splitting.
Highlights
It is imperative to find sustainable alternative energy to cope with humankind’s energy source crisis [1,2]
It is urgent to develop a new type of copper-based metal oxide photocathode, so that the Cu2O conduction band is sheared, and the photogenerated electrons are directed to the redox stable metal orbitals
The novel platinum-enriched porous CuBi2O4 nanofiber (CuBi2O4/Pt) with uniform coverage and high surface area was prepared as a photocathode through an electrospinning and electrodeposition process for efficient water splitting
Summary
It is imperative to find sustainable alternative energy to cope with humankind’s energy source crisis [1,2]. Substantial studies have revealed CuBi2O4, a multinary p-type metal oxide semiconductor that alloys Cu2O with Bi oxide, and its ternary alloy structure allows the photogenerated electrons to be directed toward redox stable metal orbitals [12] Such CuBi2O4 possesses a sufficiently narrow direct bandgap and exceptionally positive photocurrent onset potential (>1.0 V vs RHE), improving solar energy utilization [13,14,15,16]. The coupling of film-type CuBi2O4 with different noble metal decorative materials has attracted widespread attention due to its synergistic effect, which can increase photoelectrochemical activity [20] Such CuBi2O4 film can be realized by hydrothermal synthesis, chemical bath deposition [21], and a template-directed method [22]. This study provides a new idea for the integration of Pt nanoparticles and CuBi2O4 nanofibers and provides a synergistic catalyst for future solar water splitting
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
