Enhanced electrochemical kinetics of highly-oriented (111)-textured boron-doped diamond electrodes induced by deuterium plasma chemistry

Novel highly-oriented (111)-textured boron-doped diamond electrodes (BDDD) featuring high electrochemical activity and electrode stability toward electrochemical analytics were fabricated by deuterium-rich microwave plasma CVD. The high flux deuterium plasma-induced preferential formation of (111)-faceted diamond as revealed by XRD. The highly-oriented diamond surface exhibited improved boron dopant incorporation and activation, whereas the crystals showed enhanced carrier electron acceptance and donation, which accelerated the electron transfer during electrochemical redox mediation. The standard rate constant and peak-to-peak separation ΔE for the oxidation and reduction of the Fe(CN)63−/4- and Ru(NH3)62+/3+ redox probes reached ΔE values of only 60.6 and 59.8 mV, respectively. The enriched electrochemical performance of the BDDD electrodes is an advantageous feature allowing them to be applied as ultrasensitive electrodes, demonstrated here by paracetamol determination. The differential pulse voltammetry results revealed an enhanced electrochemical oxidation effect for paracetamol at the deuterium-grown (111)-rich diamond electrode. A single linear range from 1 to 125 μM along with a low detection limit of 0.76 μM were achieved.