CEA, LIST, Diamond Sensors Laboratory, F-91191 Gif-sur-Yvette, France.
Nanoscale. 2013 Oct 7;5(19):8958-62. doi: 10.1039/c3nr02492j. Epub 2013 Aug 22.
Although undoped diamond is insulating, hydrogenated bulk diamond surfaces exhibit surface conductivity under air and are electrochemically active in aqueous solutions. Due to their large surface/volume ratio, similar surface effects may exhibit a dramatic impact on the properties of nanodiamonds. Here we show that plasma-hydrogenated detonation nanodiamonds (NDs-H) display a positive zeta potential in water due to charge transfer with a redox couple involving oxygen in water. The transfer doping of NDs-H in water can be modulated by pH. Surprisingly, after acid addition, strong Coulomb coupling between NDs-H and adsorbed counterions induces the self-assembly of NDs-H into organized macro-structures reaching millimeter scale.
虽然未掺杂的金刚石是绝缘的，但氢化的大块金刚石表面在空气中表现出表面导电性，并且在水溶液中具有电化学活性。由于其大的表面积/体积比，类似的表面效应可能对纳米金刚石的性质产生显著影响。在这里，我们表明，由于涉及水中氧的氧化还原对的电荷转移，等离子体氢化爆轰纳米金刚石（NDs-H）在水中显示正的 ζ 电位。NDs-H 在水中的转移掺杂可以通过 pH 值进行调节。令人惊讶的是，在添加酸后，NDs-H 与吸附的抗衡离子之间的强库仑耦合诱导 NDs-H 自组装成达到毫米尺度的有序宏观结构。
