Composite Indium Tin Oxide Nanofibers with Embedded Hematite Nanoparticles for Photoelectrochemical Water Splitting

Abstract

Hematite is a classical photoanode material for photoelectrochemical water splitting due to its stability, performance, and low cost. However, the effect of particle size is still a question due to the charge transfer to the electrodes. In this work, we addressed this subject by the fabrication of a photoelectrode with hematite nanoparticles embedded in close contact with the electrode substrate. The nanoparticles were synthesized by a solvothermal method and colloidal stabilization with charged hydroxide molecules, and we were able to further use them to prepare electrodes for water photo-oxidation. Hematite nanoparticles were embedded within electrospun tin-doped indium oxide nanofibers. The fibrous layer acted as a current collector scaffold for the nanoparticles, supporting the effective transport of charge carriers. This method allows better contact of the nanoparticles with the substrate, and also, the fibrous scaffold increases the optical density of the photoelectrode. Electrodes based on nanofibers with embedded nanoparticles display significantly enhanced photoelectrochemical performance compared to their flat nanoparticle-based layer counterparts. This nanofiber architecture increases the photocurrent density and photon-to-current internal conversion efficiency by factors of 2 and 10, respectively.

Recent advances in nanofiber-based flexible transparent electrodes

“…Many studies have shown that doping NPs or ions into NFs can effectively improve their electrical conductivity, catalytic activity, mechanical stability, photoelectrochemical performance, etc [12,128,258,259]. Sanger et al doped Al in zinc oxide hollow NFs to effectively improve the sensitivity of gas sensors [260].…”

In–Sb Covalent Bonds over Sb2Se3/In2Se3 Heterojunction for Enhanced Photoelectrochemical Water Splitting

“…Today, with the rapid development of the global economy, environmental pollution and energy shortages need to be urgently addressed. Hydrogen is a clean and efficient renewable energy source, and among numerous hydrogen production methods, photoelectrochemical (PEC) water splitting can efficiently produce hydrogen from abundant sunlight. − Since TiO 2 was initially reported as a photoelectrode for water splitting, numerous light-absorbing semiconductor materials, such as ZnO, g-C 3 N 4 , CdS, and BiVO 4 , have been employed in PEC water splitting. Nevertheless, almost none of them are well qualified for a satisfactory light response range, environmental and human friendliness, or high corrosion resistance simultaneously.…”