A copper-based metal-organic framework/tungsten trioxide with improved coloration efficiency for electrochromic application

Copper-based metal-organic framework/tungsten trioxide (HKUST-1/WO3) was synthesized as an electrochromic material via spin coating and hydrothermal. The electrochromic studies of HKUST-1/WO3 composite revealed a high coloration efficiency (296.4 cm2/C) compared to WO3 (85.3 cm2/C) and HKUST-1 (36.7 cm2/C). HKUST-1/WO3 also demonstrated improved switching kinetics (tc = 8.3 s, tb = 2.2 s) and great optical contrast (76.6%) at 633 nm. The excellent stability of HKUST-1/WO3 was obtained over 1000 cycles with electrochromic charge retention of 85.9%. The outstanding EC performance of the HKUST-1/WO3 composite was achieved due to the synergistic effect between the HKUST-1 and WO3, which contributed to an efficient Li+ ion insertion/deinsertion for the coloration/bleaching process of the composite.