3D hierarchically porous NiO/NF (Ni foam) was synthesized by a facile hydrothermal method and a subsequent annealing process in different atmospheres for the simultaneous Cr(VI) removal and hydrogen generation from wastewater by the electrocoagulation method. O₂ atmosphere for annealing increased the Ni³⁺ content in NiO, thus led to an enhanced electrostatic interaction with Cr(VI)/OH⁻ anions and subsequently increased the Cr(VI) adsorption and Ni hydroxide flocculant production. Thus, the NiO-O₂/NF electrode exhibited the best Cr(VI) removal performance of 99.5% within 20 min at the applied potential of 0.97 V vs. RHE, along with a hydrogen generation rate of 1.1 mmol g⁻¹ h⁻¹. The removal mechanism was suggested, including the reduction of Cr(VI) to Cr(III), direct complexation reactions with the freshly produced amorphous Ni hydroxides, and adsorption on NiO-X/NF electrodes.

通过简便的水热法和随后的退火工艺在不同的气氛中合成了3D分层多孔NiO / NF（Ni泡沫），以通过电凝法同时去除废水中的Cr（VI）和氢。ø ₂气氛退火增加的Ni ³⁺以NiO含量，从而导致增强的静电与铬（VI）/ OH相互作用^-阴离子和随后增加的Cr（VI）的吸附和Ni氢氧化物絮凝剂的生产。因此，NiO-O ₂ / NF电极在0.97 V vs. RHE的施加电势下，在20分钟内表现出最佳的Cr（VI）去除性能，为99.5％，氢气产生速率为1.1 mmol g ^-1  h^-1。提出了去除机理，包括将Cr（VI）还原为Cr（III），与新鲜生成的非晶态Ni氢氧化物直接络合反应以及在NiO-X / NF电极上的吸附。