Synthesis of free-metal composites g-CN/GQDs with enhanced photocatalytic degradation of tetracyclineKai Zheng, Jianan Chen, Xue Gao, Xiaoqing Cao, Shan Wu and Jixin SuE3S Web Conf., 293 (2021) 01019DOI: https://doi.org/10.1051/e3sconf/202129301019