Electronic Supplementary Information from From two-dimensional graphene oxide to three-dimensional honeycomb-like Ni<sub>3</sub>S<sub>2</sub>@graphene oxide composite: insight into structure and electrocatalytic properties WeiXinting liYueqiang XuWenli ZhangKaixuan YinJie ShiShaozhen WeiJiazhen DiFangfang GuoJunxue WangCan ChuChaofan SuiNing ChenBaoli ZhangYingtian HaoHongguo ZhangXianxi ZhaoJinsheng ZhouHuawei WangShuhao 2017 The normalized photovoltaic parameters based on 3D honeycomb-like Ni3S2@GO synthetized by different concentration of Ni(NO<sub>3</sub>)<sub>2</sub>