Nano-sized boron-doped diamond (BDD) enabled electrodes

Inventors

Westerhoff, Paul K. • Garcia-Segura, Sergio • Sinha, Shahnawaz • Bansal, Rishabh • Verduzco, Rafael • Wong, Michael S.

Abstract

An electrode includes an electrically conductive substrate with a coating containing boron-doped diamond (BDD) nanoparticles. Fabricating the electrode can include dispersing BDD nanoparticles in a solvent to yield a suspension, coating a conductive substrate with the suspension, and drying the suspension to yield the electrode. In some cases, fabricating the electrode includes combining BDD nanoparticles with a polymeric resin precursor to yield a mixture including a metal oxide, coating a conductive substrate with the mixture to yield a coated substrate, and calcining the coated substrate to yield a metal oxide coating including BDD nanoparticles. In certain cases, fabricating the electrode includes combining powdered activated carbon with polymeric linkers to yield a polymeric precursor solution, combining BDD nanoparticles with the polymeric precursor solution to yield a mixture, coating a conductive substrate with the mixture to yield a coated substrate, and crosslinking the polymeric linkers to yield the electrode.

Core Innovation

An electrode comprising an electrically conductive substrate and a coating that includes boron-doped diamond (BDD) nanoparticles is disclosed. Fabrication approaches for applying nano-BDD to substrates are described [procedural detail omitted for safety]. The coating can include a polymer and powdered activated carbon together with boron-doped diamond nanoparticles comprising between about 10 and about 80,000 ppm boron. The BDD nanoparticles can have a diameter in a range between about 10 nm and about 200 nm.

The background identifies challenges in electrochemical water treatment and sensing, including the need to selectively utilize energy to oxidize or reduce target species without energy going to competing reactions such as oxygen or hydrogen evolution, and limitations of current electrode materials. Current fabrication methods of BDD electrodes are expensive, typically require specialized equipment (e.g., chemical vapor deposition processes), and are limited to electrode substrates compatible with those specialized processes. Many carbon electrodes are earth-abundant and inexpensive but often suffer from poor electrochemical performance attributes and material durability.

Boron-doped diamond (BDD) acts like a semiconductor and demonstrates conductance similar to that of metals, includes earth-abundant elements, has a high oxygen evolution overvoltage, can degrade organic pollutants without impacting the electrode material, and has good corrosion stability even in acidic media. BDD provides a wide electrochemical potential window −1.2V to +2.5V, which the patent states is advantageous for contaminant degradation and electroanalysis and can increase faradaic efficiencies of other electrochemical reactions. Nano-BDD electrodes provide greater electroactive surface area than bulk BDD, allow for >1000× higher BDD surface area per unit area of electrodes, and enable fabrication of electrodes at <1% of the cost compared to conventional BDD electrodes.

Claims Coverage

The patent includes one independent claim with two main inventive features.

The independent claim covers an electrode formed from an electrically conductive substrate and a coating that comprises a polymer, powdered activated carbon, and boron-doped diamond nanoparticles with boron concentrations between about 10 and about 80,000 ppm.

Stated Advantages

Documented Applications