Intrinsically strained noble metal-free oxynitrides for solar photoreduction of CO2

Debtanu Maiti; Anne J Meier; Johnnie Cairns; Swetha Ramani; Karen Martinet; John N Kuhn; Venkat R Bhethanabotla

doi:10.1039/c9dt01986c

Intrinsically strained noble metal-free oxynitrides for solar photoreduction of CO₂

Dalton Trans. 2019 Sep 7;48(33):12738-12748. doi: 10.1039/c9dt01986c. Epub 2019 Aug 7.

Authors

Debtanu Maiti¹, Anne J Meier², Johnnie Cairns¹, Swetha Ramani³, Karen Martinet¹, John N Kuhn⁴, Venkat R Bhethanabotla⁴

Affiliations

¹ Department of Chemical & Biomolecular Engineering, University of South Florida, Tampa, FL-33620, USA. jnkuhn@usf.edu bhethana@usf.edu.
² Department of Chemical & Biomolecular Engineering, University of South Florida, Tampa, FL-33620, USA. jnkuhn@usf.edu bhethana@usf.edu and Laboratory - Development and Testing Division, NASA Kennedy Space Center, FL-32899, Mail Stop NE-L3, USA.
³ Department of Chemistry, University of South Florida, Tampa, FL-33620, USA.
⁴ Department of Chemical & Biomolecular Engineering, University of South Florida, Tampa, FL-33620, USA. jnkuhn@usf.edu bhethana@usf.edu and Department of Chemistry, University of South Florida, Tampa, FL-33620, USA.

PMID: 31389443
DOI: 10.1039/c9dt01986c

Abstract

Metal oxynitrides show promising activity for photocatalytic solar water splitting and CO₂ reduction under solar irradiance. Precise control of cation ratios in oxynitrides is an inevitable challenge that needs to be overcome for achieving effective band gap tuning. Here we report the density functional theory-based calculations for the intricate structure-function relationships of Zn-Ga based oxynitrides and correlate the results with the experimental parameters. Crucial material property descriptors such as elemental composition, intrinsic lattice strain, and vacancy defects were exploited during the synthesis to achieve stable oxynitride photocatalysts that demonstrated CO₂ conversion to CO under simulated solar light, without any noble metal impregnation. The highest CO production rate surpassed that of TiO₂ under the same conditions. This work inspires future research on oxynitride materials with tailored optical properties and sustainable photocatalytic activity which enables their large scale applications.