Lowered phase transition temperature and excellent solar heat shielding properties of well-crystallized VO2 by W doping

Nan Shen; Bingrong Dong; Chuanxiang Cao; Zhang Chen; Jianjun Liu; Hongjie Luo; Yanfeng Gao

doi:10.1039/c6cp05143j

Lowered phase transition temperature and excellent solar heat shielding properties of well-crystallized VO₂ by W doping

Phys Chem Chem Phys. 2016 Oct 12;18(40):28010-28017. doi: 10.1039/c6cp05143j.

Authors

Nan Shen¹, Bingrong Dong¹, Chuanxiang Cao², Zhang Chen², Jianjun Liu³, Hongjie Luo⁴, Yanfeng Gao⁵

Affiliations

¹ Shanghai Institute of Ceramics (SIC), Chinese Academy of Sciences (CAS), No. 1295 Dingxi Road, Changning District, Shanghai, 200050, China and University of Chinese Academy of Sciences, Beijing, 100049, China.
² School of Materials Science and Engineering, Shanghai University, No. 99 Shangda Road, Shanghai, 200444, China. yfgao@shu.edu.cn.
³ Shanghai Institute of Ceramics (SIC), Chinese Academy of Sciences (CAS), No. 1295 Dingxi Road, Changning District, Shanghai, 200050, China.
⁴ Shanghai Institute of Ceramics (SIC), Chinese Academy of Sciences (CAS), No. 1295 Dingxi Road, Changning District, Shanghai, 200050, China and School of Materials Science and Engineering, Shanghai University, No. 99 Shangda Road, Shanghai, 200444, China. yfgao@shu.edu.cn.
⁵ School of Materials Science and Engineering, Shanghai University, No. 99 Shangda Road, Shanghai, 200444, China. yfgao@shu.edu.cn and Huaiyin Institute of Technology, Huaian 223003, China.

PMID: 27711687
DOI: 10.1039/c6cp05143j

Abstract

Monoclinic VO₂ (M) is a key material for energy-efficient smart window applications. Fine crystalline VO₂ particles with an ambient phase transition temperature are urgently required to achieve excellent properties including high luminous transmittance and solar heat shielding ability. Moreover, the anti-oxidation ability is regarded as a significant factor which determines the lifetime of VO₂-based products. In this paper, well-crystallized W-doped VO₂ with low phase transition temperature, excellent solar heat shielding ability and considerable anti-oxidation ability was synthesized by a solid-state reaction process. The phase transition temperature was reduced from 67.3 °C to 10.8 °C at 2.0% W doping with an efficiency of -28.1 °C per at%. Importantly, an excellent balance between the phase transition temperature and the latent heat was obtained at high doping levels (1.5-2.0%). Furthermore, W-doped VO₂ particles exhibited a significantly longer exposure time (more than 5 h) at 300 °C in air than the previously reported 2 h in the literature, and the corresponding derived composite foils showed excellent luminous transmittance and solar heat shielding properties (T_lum = 49.9% and T_sol = 44.8% for 2.0% W doping).