Synthesis of One-Dimensional Potassium Tungsten Bronze with Excellent near-Infrared Absorption Property

Abstract

Potassium tungsten oxide nanofibers were successfully synthesized via a facile hydrothermal reaction route in the presence of sulfate. After reduction under a reductive atmosphere of H(2)(5 vol %)/N(2), the potassium tungsten oxide transformed to potassium tungsten bronze. Because of the lack of free electrons, the potassium tungsten oxide (K(x)WO(3+x/2)) showed no NIR shielding performance; however, the potassium tungsten bronze (K(x)WO(3)) showed promising optical characteristics such as high transmittance for visible light, as well as high shielding performance for near-infrared lights, indicating its potential application as a solar filter. Meanwhile, the potassium tungsten bronze (K(x)WO(3)) showed strong absorption of near-infrared light and instantaneous conversion of photoenergy to heat.

Hydrothermal synthesis of K2W4O13 nanowire with high H2S gas sensitivity

“…The K x WO 3 exhibit wide range of electronic properties and thus have been investigated for potential applications as electrodes in electrochemical devices, gas sensor and solar filter [8][9][10][11]. For gas-sensing application, it has been reported that the K 0.475 WO 3 nanosheet exhibited good responses to 10-50 ppm H 2 S (10-40) and 10-60 ppm acetone at 300°C [10].…”

“…For gas-sensing application, it has been reported that the K 0.475 WO 3 nanosheet exhibited good responses to 10-50 ppm H 2 S (10-40) and 10-60 ppm acetone at 300°C [10]. Nanostructured potassium tungsten oxides have been synthesized in variety of shapes such as nanosheet [10], nanorod [12] and nanowire/nanofiber [11,13].…”

Ordered and twinned structure in hexagonal-based potassium tungsten bronze nanosheets

“…Tungsten bronzes have attracted extensive attention in the past few decades owing to their unique crystal structures and interesting electrical, electrochromism, optical and superconducting properties (Sienko & Morehouse, 1963;Tsuyumoto, 1993;Magné li, 1953;Hussain, 1997;Guo, Yin, Huang & Sato, 2011;Lee et al, 1997;Cadwell et al, 1981), which have made them promising materials that could be widely applied in field electron emission, electronic devices, humidity sensors, gas sensors, heat ray shielding materials etc. (Zheng et al, 2008;Wechter et al, 1972;Dobson & Comer, 1987;Tsuyumoto, 1996;Zhang et al, 2007;Guo et al, 2010Guo et al, , 2012Guo, Yin, Yan & Sato, 2011).…”

“…Variation of the reaction conditions resulted in a number of nanoscale product morphologies, including nanorods and nanosheets with hexagonal crystal structure (Zhang et al, 2007;Qi et al, 2003;Zheng et al, 2008;Fan et al, 2001;Gu et al, 2006Gu et al, , 2011Zivkovic et al, 2009). Superstructure was also observed in nanomaterials (Guo, Yin, Huang & Sato, 2011;Gillet et al, 2005;Wu et al, 2006) but has not been systematically analyzed. As is well known, defects in crystals can be crucial for determining their properties.…”

Synthesis of Potassium Tungsten Bronze Nanosheets by Phase Transformation

“…To enhance their properties, nanostructured alkali metal tungsten oxides and alkali metal tungsten bronzes have been prepared by various techniques. Potassium tungsten bronze nanowires were synthesized by reaction of citric acid and K 2 SO 4 directly, or by annealing potassium tungsten oxide nanowires prepared by hydrothermal method under H 2 /N 2 atmosphere . Oriented potassium tungsten oxide nanowires were grown on W substrate by a physical heating treatment .…”