In this comparative study, we investigated the facile and cost-effective fabrication of non-noble transition metal-based bimetallic and trimetallic 3D coatings as highly efficient and sustainable electrocatalysts for the hydrogen evolution reaction (HER) in alkaline media (pH ≈ 14). These coatings were fabricated on thin titanium substrates (0.127 mm thickness, 1×1 cm\(^{2}\)) using an electrochemical deposition method through a dynamic hydrogen bubble template technique. The as-fabricated bimetallic NiMo/Ti catalyst exhibited a unique cedar leaf-like surface morphology while the NiMn/Ti catalyst demonstrated a nodule-like structure. In contrast, the trimetallic NiCoMn/Ti electrocatalyst displayed a unique cauliflower curd-shaped micro-sized nodular architecture. The HER activity of these fabricated catalysts was investigated by using Linear Sweep Voltammetry (LSV) in the alkaline environment at different temperatures. Also, the electrocatalysts were characterized by scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES).
From a comparative point of view, the as-prepared NiCoMn/Ti electrocatalyst exhibits excellent HER activity in alkaline media with a low overpotential of 139 mV to reach a current density of 10 mA cm\(^{-2}\), whereas this benchmark current density was attained by NiMn/Ti and NiMo/Ti electrocatalysts with higher overpotentials of 220.3 mV and 288 mV, respectively. The current densities increased with an increase in temperatures from 25 °C to 75 °C for all three electrocatalysts. These non-noble metal-based catalysts have displayed excellent long-term stability at a constant potential of -0.232 V (vs. RHE) and a constant current density of 10 mA cm\(^{-2}\) and a multi-step chronopotentiometry test with current densities ranging from 20 mA cm\(^{-2}\) to 100 mA cm\(^{-2}\), indicating sustainable durability and suitability for practical alkaline water splitting applications.