In contrast, highly oxidized phosphorene [PhosO(1:2) and PhosO(1:1)] show a not ideal adsorption behavior as a result of the strong negatively charged surface, leading to a strong adsorbent-adsorbate electrostatic repulsion, and consequently, decreasing the adsorption performance (Fig. ). For instance, the adsorption energy of As(V) 2-onto PhosO(1:2) is decreased with respect to the uptake onto medium-oxidized PhosO (0.5 v. 1.8 eV) . Then, a high/full phosphorene oxidation does not provide additional adsorption performance compared to medium-oxidized phosphorene.