Dispelling the myth of passivated codoping in TiO2

DOI: 10.1021/acs.chemmater.9b00257

Authors: Benjamin A. D. Williamson (University College London) , John Buckeridge (University College London) , Nicholas P. Chadwick (University College London; Bio Nano Consulting) , Sanjayan Sathasivam (University College London) , Claire J. Carmalt (University College London) , Ivan P. Parkin (University College London) , David O. Scanlon (University College London; Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemistry Of Materials

State: Published (Approved)
Published: March 2019

Abstract: Modification of TiO2 to increase its visible light activity and promote higher performance photocatalytic ability has become a key research goal for materials scientists in the past two decades. One of the most popular approaches proposed this as “passivated codoping”, whereby an equal number of donor and acceptor dopants are introduced into the lattice, producing a charge neutral system with a reduced band gap. Using the archetypal codoping pairs of [Nb+N] and [Ta+N] doped anatase, we demonstrate using hybrid density functional theory that compensated codoping is not achievable in TiO2. Our results indicate that the natural defect chemistry of the host system (in this case n-type anatase TiO2) is dominant, and so concentration parity of dopant types is not achievable under any thermodynamic growth conditions. The implications of compensated codoping for band gap manipulation in general are discussed.

Journal Keywords: Impurities; Oxides; Defects; Minerals; Electrical conductivity

Diamond Keywords: Photocatalysis; Semiconductors

Subject Areas: Chemistry, Materials


Technical Areas:

Added On: 25/03/2019 14:20

Documents:
jkj4555.pdf

Discipline Tags:

Physical Chemistry Catalysis Chemistry Materials Science Chemical Engineering Engineering & Technology

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