Nickel phosphides electrodeposited on TiO2 nanotube arrays as electrocatalysts for hydrogen evolution

Nickel phosphide (NiPx)-based nanocomposites emerged as a new class of highly promising non-noble-metal-based electrocatalysts for hydrogen evolution reactions (HER). However, conventional synthesis for this type of nanocomposite involves using harsh organic solvents and multiple complicated procedures as well as the release of concomitant toxic gases, thus significantly restricting their practical applications. To explore a much greener and more sustainable synthesis approach, a facile one-step electrodeposition technique for nanoelectrode toward HER is developed in this research, in which amorphous NiPx is anchored onto TiO2 nanotube arrays to form a nanocomposite material. The synthesized nanocomposites have a synergistic coupling of material properties in two components of the nanocomposites, with an enhanced charge transfer and electrochemically active surface areas. Because of such unique characteristics, the system exhibits a remarkable catalytic reduction activity and superior stability in alkaline electrolytes, requiring overpotentials of 104 and 129 mV to achieve current densities of 10 and 20 mA cm-2, respectively. This method provides an effective and green approach to fabricate NiPx-based nanocomposites with enhanced HER performances.