Polyoxotungstate intercalated self-assembled nanohybrids of Zn-Cr-LDH for room temperature Cl2 sensing

This article reports the preparation of mesoporous layered nanohybrids of zinc chromium layered double hydroxide (Zn-Cr-LDH) and polyoxotungstate (POW) anions via an exfoliation-reassembling process. The hybridization of Zn-Cr-LDH and POW anions leads to forming a layer-by-layer intercalated structure with a randomly interconnected mesoporous nanoplate network composed of ‘restacked POW intercalated Zn-Cr-LDH nanosheets’ (Zn-Cr-WO). The gas-sensing performance of the pristine Zn-Cr-LDH and Zn-Cr-WO was investigated for oxidizing (NO2 and Cl2), and reducing (LPG, H2, H2S, CO and NH3) gases at room temperature. The Zn-Cr-WO nanohybrids displayed the highest selectivity towards Cl2. The Cl2 gas response for the pristine Zn-Cr-LDH is 25.2% which further increased to 66.8% after hybridization with POW anions. The Zn-Cr-WO nanohybrids showed fastest response and recovery times of 5 and 133 s, respectively, at room temperature.