Transition metal hydroxides (M‐OH) and their heterostructures (X|M‐OH, where X can be a metal, metal oxide, metal chalcogenide, metal phosphide, etc.) have recently emerged as highly active electrocatalysts for hydrogen evolution reaction (HER) of alkaline water electrolysis. Lattice hydroxide anions in metal hydroxides are primarily responsible for observing such an enhanced HER activity in alkali that facilitate water dissociation and assist the first step, the hydrogen adsorption. Unfortunately, their poor electronic conductivity had been an issue of concern that significantly lowered its activity. Interesting advancements were made when heterostructured hydroxide materials with a metallic and or a semiconducting phase were found to overcome this pitfall. However, in the midst of recently evolving metal chalcogenide and phosphide based HER catalysts, significant developments made in the field of metal hydroxides and their heterostructures catalysed alkaline HER and their superiority have unfortunately been given negligible attention. This review, unlike others, begins with the question of why alkaline HER is difficult and will take the reader through evaluation perspectives, trends in metals hydroxides and their heterostructures catalysed HER, an understanding of how alkaline HER works on different interfaces, what must be the research directions of this field in near future, and eventually summarizes why metal hydroxides and their heterostructures are inevitable for energy‐efficient alkaline HER.

Alongside rare‐earth metals, Ni, Fe, Co, Cu are some of the critical materials that will be in huge demand thanks to growth in clean‐energy sector. Herein scrap stainless steel wires (SSW) from worn‐out tires are employed as a support material for catalyst integration in the hydrogen evolution reaction (HER). In addition, SSW by corrosion engineering is exercised as an in situ formed freestanding robust electrode for the oxygen evolution reaction (OER). By superficial corrosion of SSW, inherent active species are unmasked in the form of Ni/FeOOH nanocrystallites displaying efficient water oxidation by reaching 500 mA cm−2 at low overpotential (η500) of 287 mV in 1 m KOH. Similarly, cathode scrap SSW with active (alloy) coatings of MoNi4 catalyzes the HER at η‐200 = 77 mV, with a low activation energy (Ea = 16.338 kJ mol−1) and high durability of 150 h. Promisingly, when used in industrial conditions, 5 m KOH, 343 K, these electrodes demonstrate abnormal activity by yielding high anodic and cathodic current density of 1000 mA cm−2 at η = 233 mV and η = 161 mV, respectively. This work may inspire researchers to explore and reutilize high‐demand metals from scrap for addressing critical material shortfalls in clean‐energy technologies.

Disposal of e‐wastes in prescribed landfills poses serious environmental concerns at both a local and global scale. Recovering valuable materials from e‐wastes and utilizing them for development of eco‐design devices guides one to a more productive way of managing wastes. Recycled copper is capable of retaining its intrinsic properties and can be reused with same expectation of performances; capitalizing on this fact, herein, it is attempted to utilize copper from e‐waste as an economically viable catalytic substrate for overall water splitting. Upon deposition of amorphous nickel cobalt phosphide films, the scrap copper wires are highly efficient for catalyzing hydrogen and oxygen evolution reaction at low overpotential (10η‐HER = 178 mV, 10η‐OER = 220 mV), and considerably promote water catalysis at 1.59 V@10 mA cm−2. Moreover, the electrodes demonstrate long‐term stability in alkaline electrolyte that can potentially be employed for large‐scale electrolyzer application. The proposed electrode architecture, by the explicit growth of bimetallic phosphide on highly conductive Cu substrate, facilitates fast electron transport and promises a minimum contact resistance between electrocatalyst and current collector. This work paves the way for development of environmentally sound electrode materials from e‐waste that can be exercised for a myriad of other clean energy reactions.