1. Shaanxi Key Laboratory of Degradable Medical Material, Shaanxi Key Laboratory of Physico‐inorganic Chemistry, Northwest University, Xi'an 710069, Shaanxi, P. R. China
2. Department of Chemistry and Centre for Advanced Luminescence Materials, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong, P. R. China
3. Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712‐0165, USA