Catalytic activity of platinum nanoparticles on highly boron-doped and 100-oriented epitaxial diamond towards HER and HOR
Catalytic activity of platinum nanoparticles on highly boron-doped and 100-oriented epitaxial diamond towards HER and HOR
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DOI：
10.1039/c1cp20852g
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发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Stimming, Ulrich
中科院分区：
文献类型：
--
作者：
Bruelle, Tine;Denisenko, Andrej;Stimming, Ulrich
铂纳米粒子负载在硼掺杂的单晶金刚石表面被用作模型系统，以调查的催化活性相对于颗粒形态，颗粒密度和金刚石衬底的表面制备的影响。我们报告这些Pt/金刚石电极的制备，表征和有关析氢反应（HER）和氢氧化反应（HOR）的活性。在（100）取向金刚石衬底上外延生长了两种硼掺杂量大于10（20）cm（-3）的金刚石层，并进行了湿化学氧化和射频氧等离子体处理。使用恒电位双脉冲技术进行Pt的电化学沉积，该技术允许颗粒尺寸在高度为1 nm和15 nm之间以及表观半径为5 nm和50 nm之间的范围内变化，同时保持颗粒密度恒定。在相同的沉积参数下，等离子体处理表面上较高的成核密度可能与等离子体诱导的表面缺陷有关。电化学表征表明，铂颗粒作为纳米电极，并与金刚石基板形成欧姆接触。铂纳米颗粒的HER和HOR的催化活性不依赖于颗粒尺寸，直到颗粒高度接近1 nm。所制备的金刚石上的Pt（100）样品显示出与本体铂类似的铂比活性。因此，在保持活性恒定的同时，金刚石上分散良好的颗粒提供了优化的表面与材料比。
Platinum nanoparticles supported on boron-doped single-crystalline diamond surfaces were used as a model system to investigate the catalytic activity with respect to the influence of particle morphology, particle density and surface preparation of the diamond substrates. We report on the preparation, characterization and activity regarding hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) of these Pt/diamond electrodes. Two kinds of diamond layers with boron doping above 10(20) cm(-3) were grown epitaxially on (100)-oriented diamond substrates; post-treatments of wet chemical oxidation and radio frequency (rf) oxygen plasma treatments were applied. Electrochemical deposition of Pt was performed using a potentiostatic double-pulse technique, which allowed variation of the particle size in the range between 1 nm and 15 nm in height and 5 nm and 50 nm in apparent radius, while keeping the particle density constant. Higher nucleation densities on the plasma processed surface at equal deposition parameters could be related to the plasma-induced surface defects. Electrochemical characterization shows that the platinum particles act as nanoelectrodes and form an ohmic contact with the diamond substrate. The catalytic activity regarding HER and HOR of the platinum nanoparticles exhibits no dependence on the particle size down to particle heights of similar to 1 nm. The prepared Pt on diamond(100) samples show a similar platinum-specific activity as bulk platinum. Therefore, while keeping the activity constant, the well-dispersed particles on diamond offer an optimized surface-to-material ratio.