Tuning the Electronic and Optical Properties of Graphene via Doping to Realize Nitrogen Dioxide Sensing: A Computational Study - Lei Luo; Hongqiang Zhu; Kaihui Yin; Zebang Wu; Fengxia Xu; Tianjun Gao; Yuanxia Yue; Jianjun Chen; Qing Feng; Ying Yang; Weiyao Jia (ACS Omega)