Enhanced Hydrogen Evolution Efficiency Achieved by Atomically Controlled Platinum Deposited on Gold Nanodendrites with High-Index Surfaces
Ying-Huang Lai,1*Sin-Ren Li,1# Swathi M G,1#Hsiao-Tzu Chang,1# Yu-Bin Huang,1 Yen-Ken Li,1 Yu-Mei Chen,1 Shivaraj B. Patil,1Shu-Yi Chang,1 Po-Kai Chen,1 Chia-Che Chang,1 Yi-Chia Chen,1 Chih-Wen Pao,2 Jeng-Lung Chen,2 Chuan-Yu Wei,3 I-Kuan Lin,3 Hung-Lung Chou,4Chun-Jen Su,2U-Ser Jeng,2,5 Tsung-Rong Kuo,6 Cheng-Yen Wen,3,7,8 Di-Yan Wang1*
There have been lots of studies on hydrogen evolution reaction (HER) catalytic activity using ultralow loading of Pt catalysts or even Pt single atom catalysts as well. However, Pt single atom deposited on the surface of the carbon or metal oxide material showed some drawbacks, such as high possibility of Pt desorption from the supported material in the electrolyte. Besides, from the reaction mechanism perspective, each Pt atom in this type of catalyst was too far to achieve high HER efficiency via Tafel reaction pathway. In this work, gold nanodendrites (Au NDs) with high facet surface was chosen as the supported materials for studying the relation between the low loading amount of Pt atoms and reaction mechanism of HER activity. The atomic deposition of Pt atoms on the surface of Au NDs can be controlled effectively by using a constant-current synthetic method. It’s found that the HER electrocatalytic activity of ultralow Pt loading catalyst, Pt atoms to total surface atoms of Au NDs (O-Pt on Au NDs) was only 5.5%, could achieve high efficiency via Tafel reaction pathway, showing a low overpotential of ~18 mV at a current density of 10 mA cm−2 and a small Tafel slope of ~31 mV dec-1 which is close to that of commercial Pt/C with 20wt% Pt. Confirmed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Pt loading amount of O-Pt on Au NDs was ~3.8 ± 0.2mg/cm2 on a physical area of carbon fibre paper. The turnover frequency (TOF) of O-Pt on Au NDs was achieved to be 40.1 ± 2.5H2 s−1 at 50 mV. This work provides a feasible approach to control atomic deposition of Pt element on the specific substrate as active catalysts for various catalytic applications.