Structure and Properties of Hydrogen-Charged Electrochromic Nb₂O₅ Ceramics

Abstract:

Nb2O5 ceramic pellets were prepared through sintering and hydrogen was introduced into Nb2O5 pellets through a process known as electrochemical hydrogen charging, in which Nb2O5 acted as the cathode in a 0.01 M NaOH solution. The color of Nb2O5 was found dramatically darkened after the treatment while X-ray diffraction indicated that there was no change in the crystal structure. I-V and R-T measurements showed that the resistivity was greatly decreased after hydrogen charging and the resistivity exhibited a negative-temperature-coefficient (NTC). It was proposed that hydrogen can be incorporated into Nb2O5 lattice and occupies at some interstitial site. Nb5+ of Nb2O5 is partially reduced to Nb4+ by hydrogen and the NTC-type conduction results from electron transfer between Nb5+ and Nb4+ through a hopping mechanism.

• Periodical: Advanced Materials Research (Volumes 79-82)
• Pages: 1619-1622
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.79-82.1619
• Online since: August 2009
• Authors: Ming Jian Ding, Wan Ping Chen, Yan Hong Gu, Yu Wang
• Keywords: Donor, Electrochromic, Hydrogen, Nb₂O₅, Resistivity

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