Tellurium Nanosphere/Hematite Hybrid Thin Films with Enhanced Light Absorption for Efficient Photocatalysis

Abstract

As a semimetal, tellurium (Te) shows metallic and dielectric properties in the UV and visible ranges, respectively, and has potential as a broad-band light absorber. In this paper, plasmonic−semiconductor hybrid nanoscale films consisting of Fe 2 O 3 thin films and Te nanospheres are designed and demonstrated. Te clusters are proved to have an enhancement of the electric near-field in a broad UV−vis−NIR spectrum, which facilitates light absorption and charge separation in photoelectrocatalysis. The thickness of Fe 2 O 3 films is adjusted from 22 to 137 nm. The photocurrent density enhancement factor of Te-modified films is 13 times higher than that of 22 nm Fe 2 O 3 films. Particularly, a Te-decorated Fe 2 O 3 ultrathin film exhibits photoelectrochemical activity comparable to that of bulk Fe 2 O 3 , suggesting significant near-field enhancement from plasmon modes of the Te clusters. It is found that the Te cluster decoration led to a significant decrease of the charge transfer resistance, demonstrating that the Te clusters could boost the formation rate and suppress the recombination rate of electron−hole pairs. The hybridization of Te nanoparticles with nanoscale semiconductor films represents an efficient way to enhance the solar energy conversion efficiency.

Photocatalytic Cleavage of C–H Bonds: A Case Study of Formaldehyde Photodegradation from Density Functional Theory

“…Conventional techniques of thermocatalysis and electrocatalysis are sufficient to achieve the goal , but require high energy input and/or additional catalytic equipment, which are more suitable for large-scale VOC elimination in industrial processes. – By contrast, photocatalytic VOC degradation can deeply oxidize organic compounds such as formaldehyde and benzene at room temperature without extra energy consumption and has great application potential for indoor confined spaces and low VOC concentration scenarios. – Many materials, such as TiO 2 , Fe 2 O 3 , ZnO, WO 3 , CdS, etc. , have been discovered as promising photocatalysts, – among which TiO 2 is widely used for VOC degradation and wastewater treatment due to its excellent photocatalytic activity, nontoxicity, and good photostability. , …”