They're overselling the science. This is certainly not the first time anyone has used non-precious metals to split water at low voltages. Both Ni oxide and Ni-F

They're overselling the science. This is certainly not the first time anyone has used non-precious metals to split water at low voltages. Both Ni oxide and Ni-Fe oxide systems that they use in their paper are well known in the literature. Ni oxides have been published back in the 1950s while Ni-Fe oxide catalysts were introduced in the 1980s. However, they do claim that their NiO/Ni/CNT system is novel, which may be true. In their experimental setup, they target 20 mA/cm2 current density. To achieve that, they can just increase the amount of catalyst they use. The geometric area (cm2) will remain the same, but the surface area will increase which will correspondingly raise current density. For example, one can stack sheets of carbon aerogel to achieve the same current density.