With the rapid industrialization and commercial applications, increasing amounts of pollutants are released into the natural environment, resulting in numerous pollution issues. The efficient removal of heavy metal ions from wastewater is crucial to human health and environmental pollution cleanup. To understand the physicochemical behavior of heavy metal ions in the environment, information related to the speciation, structures and sorption of heavy metal ions at solid/water interface is crucial, which is helpful for evaluating their behavior in the environment. The high surface area and large amounts of oxygencontaining functional groups make graphene oxides suitable materials for the efficient elimination of heavy metal ions from aqueous solutions. The sorption of Ni(II) on graphene oxides is studied by batch technique and theoretical calculation, and the results show that the interaction of Ni(II) with graphene oxides is mainly dominated by outer-sphere surface complexation and ion exchange at low pH, and by inner-sphere surface complexation at high pH, which is evidenced by the DFT calculations that the sorption of Ni(II) is mainly attributed to the –COH and –COC groups with high binding energy (see the article by Yuantao Chen, Wei Zhang, Shubin Yang, Aatef Hobiny, Ahmed Alsaedi & Xiangke Wang on Pages 412–419).