The sample underwent an initial weight loss of ~3.7%, which corresponds to the broad endothermic peak at 25 °C–250 °C in Fig. 2, which can be attributed to the elimination of water [26]. A strong endothermic peak starting at ~290 °C was also observed, accompanied by a significant weight loss of ~9.7%, which was aroused by the decomposition of Mg(OH)2[27].