*4.1. Materials*

Zirconium (IV) oxynitrate hydrate (ZrO(NO3)2·H2O) and Manganese nitrate (Mn(NO3)2) solution 50 wt.% were purchased from Chengdu Hua Xia Chemical Reagent Co., Ltd. (Chengdu, China). Ammonia (NH3·H2O) (25~28%) reagent was purchased from Chengdu Ke Long chemicals Co., Ltd (Chengdu, China). All the reagents are an analytical reagent (AR), with no need for further treatment.
