Co2 conversion with nitride semiconductor-metal interface

Abstract

A catalytic device includes a substrate having a surface, an array of conductive projections supported by the substrate and extending outward from the surface of the substrate, each conductive projection of the array of conductive projections including a nitride semiconductor, and a plurality of nanoclusters disposed over the array of conductive projections, each nanocluster of the plurality of nanoclusters including a metal. Each nanocluster of the plurality of nanoclusters is coupled to a respective conductive projection of the array of conductive projections via an oxidized interface. The oxidized interface includes an oxide species of the metal. The oxidized interface further includes an oxynitride species based on the nitride semiconductor.

What is claimed is: 
     
         1 . A catalytic device comprising:
 a substrate having a surface;   an array of conductive projections supported by the substrate and extending outward from the surface of the substrate, each conductive projection of the array of conductive projections comprising a nitride semiconductor; and   a plurality of nanoclusters disposed over the array of conductive projections, each nanocluster of the plurality of nanoclusters comprising a metal;   wherein:
 each nanocluster of the plurality of nanoclusters is coupled to a respective conductive projection of the array of conductive projections via an oxidized interface; 
 the oxidized interface comprises an oxide species of the metal; and 
 the oxidized interface further comprises an oxynitride species based on the nitride semiconductor. 
   
     
     
         2 . The catalytic device of  claim 1 , wherein the oxidized interface is configured for catalytic conversion of carbon dioxide (CO 2 ). 
     
     
         3 . The catalytic device of  claim 1 , wherein each nanocluster of the plurality of nanoclusters has a distorted lattice. 
     
     
         4 . The catalytic device of  claim 1 , wherein each nanocluster of the plurality of nanoclusters has a defective surface. 
     
     
         5 . The catalytic device of  claim 1 , wherein the oxidized interface has a sub-nanometer thickness. 
     
     
         6 . The catalytic device of  claim 1 , wherein surfaces of each nanocluster of the plurality of nanoclusters not at the oxidized interface are not oxidized. 
     
     
         7 . The catalytic device of  claim 1 , wherein each conductive projection of the array of conductive projections is covered by the oxynitride species away from the nanoclusters. 
     
     
         8 . The catalytic device of  claim 1 , wherein the metal is a d-block metal. 
     
     
         9 . The catalytic device of  claim 1 , wherein the metal is copper. 
     
     
         10 . The catalytic device of  claim 1 , wherein the nitride semiconductor is a III-nitride semiconductor. 
     
     
         11 . The catalytic device of  claim 1 , wherein the nitride semiconductor is gallium nitride (GaN). 
     
     
         12 . The catalytic device of  claim 1 , wherein the nitride semiconductor is doped n-type. 
     
     
         13 . The catalytic device of  claim 1 , wherein:
 the substrate comprises a semiconductor material; and   the semiconductor material is doped to define a junction to generate charge carriers upon absorption of solar radiation.   
     
     
         14 . The catalytic device of  claim 13 , wherein each conductive projection of the array of conductive projections comprises a nanowire configured to extract the charge carriers generated in the substrate. 
     
     
         15 . An electrochemical system comprising a working electrode configured in accordance with the catalytic device of  claim 1 , and further comprising:
 a counter electrode;   an electrolyte in which the working and counter electrodes are immersed; and   a voltage source that applies a bias voltage between the working and counter electrodes;   wherein the bias voltage is set to a level for conversion of CO 2  into ethylene at the working electrode.   
     
     
         16 . The electrochemical system of  claim 15 , wherein the electrolyte lacks an organic solvent. 
     
     
         17 . A method of fabricating a catalytic device, the method comprising:
 forming an array of conductive projections on a semiconductor substrate, each conductive projection of the array of conductive projections comprising a nitride semiconductor;   depositing a plurality of nanoclusters across the array of conductive projections, each nanocluster of the plurality of nanoclusters comprising a metal; and   after depositing the plurality of nanoclusters, implementing a procedure to form an oxidized interface between each nanocluster of the plurality of nanoclusters and a respective conductive projection of the array of conductive projections;   wherein:
 the oxidized interface comprises an oxide species of the metal; and 
 the oxidized interface further comprises an oxynitride species based on the nitride semiconductor. 
   
     
     
         18 . The method of  claim 17 , wherein the oxidized interface is configured for catalytic conversion of carbon dioxide (CO 2 ). 
     
     
         19 . The method of  claim 17 , wherein implementing the procedure comprises conducting a photoelectrochemical CO 2  reduction reaction. 
     
     
         20 . The method of  claim 17 , further comprising synthesizing the plurality of nanoclusters via a solution-based chemical reduction process. 
     
     
         21 . The method of  claim 17 , wherein depositing the plurality of nanoclusters comprises implementing a drop-cast assembly process. 
     
     
         22 . The method of  claim 17 , wherein forming the array of conductive projections comprises growing an array of nanowires on the semiconductor substrate.