Scalable Synthesis of Pt Nanoflowers on Solution‐Processed MoS₂ Thin Film for Efficient Hydrogen Evolution Reaction

Abstract

Nanostructuring of Pt nanocatalysts increases the surface‐to‐volume ratio, thus enabling efficient usage of Pt for hydrogen evolution reaction (HER). Direct electrochemical reduction of Pt on the electrode can produce nanostructured Pt catalysts, which has been time‐consuming for the conventional colloidal synthesis. However, carbon‐based growth templates commonly used to create Pt nanoparticles offer limited control over morphologies and HER performance. Herein, a facile electrochemical synthesis of Pt nanoflowers (NFs) with well‐defined petals is presented. Semiconducting MoS2 nanosheets are solution processed into a film on a carbon paper (CP) to synthesize Pt NFs upon reduction of Pt precursor. The Pt NFs show higher HER activities than spherical or spiky Pt nanoparticles because of their larger active surface area and enable faster release of hydrogen bubbles during HER. By generating sulfur vacancies and MoOx on the MoS2 template using a reactive ion etching, the areal density and spatial uniformity of Pt NFs can be greatly enhanced and a mass activity can be achieved more than 10 times as high as that of the conventional Pt/C electrode. Multiple electrodes with nearly similar electrochemical properties can be repeatedly produced by using a single precursor solution, which highlights the cost‐efficiency and scalability of our synthesis strategy.

Hydrogen Spillover Intensified by Pt Sites on Single-Crystalline MoO3 Interconnected Branches for Hydrogen Evolution

“…These sharp diffraction spots and the periodicity of the measured reciprocal space lattices along both 0 and 90° evidence the single-crystallinity feature of the resultant MoO 3 product, , which is well-consistent with the TEM results. As depicted in Figure i, these morphological and structural features of s -MoO 3 , including the interconnected branches, the porous surfaces, and the stepped edges, are distinctly different to the previously reported support materials − and the commercialized MoO 3 sample ( c -MoO 3 ), which exhibits a randomly aggregated cuboid-like state (Figure S1) with a nonporous surface and a smooth edge (Figure S2).…”

Carbon–Ni6Co3Fe1 alloy hybrid foil for electromagnetic wave interference shielding in X-band and extremely low frequencies

“…The inclusion of saccharin in the electrolyte facilitated the formation of fine-grained NiCoFe deposits. 28–30 To ensure simultaneous reduction of Ni 2+ , Co 2+ , and Fe 2+ ions essential for the uniform alloy formation and to achieve a high deposition rate, we applied a constant DC voltage (4.5 V) much higher than the standard reduction potentials of these elements (−0.25 V, −0.28 V, and −0.44 V for Ni 2+ , Co 2+ , and Fe 2+ , respectively), 31 resulting in a current density ranging from −18 mA cm −2 to −19 mA cm −2 (Fig. S1, ESI†).…”

Two-dimensional materials as catalysts, interfaces, and electrodes for an efficient hydrogen evolution reaction

“…1g). 33 The reaction rate, a key variable to determine final nanostructures, can be easily controlled by the electrical resistance of the template. 33…”

“…6d–g, templates with various current levels were prepared and Pt particles were electrochemically deposited. 33 Intriguingly, the shape and area density of the Pt nanoparticles exhibited significant variations depending on the growth template used. These template-dependent differences in the Pt nanoparticle morphology can be attributed to variations in the reduction rate of Pt ions for each template.…”

“…28 Finally, 2D metallic materials have been used as conductive electrodes or templates for the synthesis of other catalytic materials with controlled nanoscale morphologies. 33…”