Method for water splitting with a perovskite electrode

Abstract

An electrode includes a transparent substrate, and a layer of a nanostructured material at least partially covering a surface of the transparent substrate. The nanostructured material includes defective perovskite nanostructures (DPNSs) in the form of nanoplates having an average particle size in a range of 10 to 100 nanometers (nm), an interplanar spacing d(101) of the (101) plane in a range of 0.3 to 0.4 nm, and an interplanar spacing d(104) of the (104) plane in a range of 0.2 to 0.3 nm. A method of making the electrode.

1 . (canceled) 
     
     
         2 . The method of claim  19 , wherein the transparent substrate is a glass substrate, and wherein the glass substrate is at least one selected from the group consisting of a fluorine doped tin oxide (FTO) glass substrate, a tin doped indium oxide (ITO) glass substrate, an aluminum doped zinc oxide (AZO) glass substrate, a niobium doped titanium dioxide (NTO) glass substrate, an indium doped cadmium oxide (ICO) glass substrate, an indium doped zinc oxide (IZO) glass substrate, a fluorine doped zinc oxide (FZO) glass substrate, a gallium doped zinc oxide (GZO) glass substrate, an antimony doped tin oxide (ATO) glass substrate, a phosphorus doped tin oxide (PTO) glass substrate, a zinc antimonate glass substrate, a zinc oxide glass substrate, a ruthenium oxide glass substrate, a rhenium oxide glass substrate, a silver oxide glass substrate, and a nickel oxide glass substrate. 
     
     
         3 . The method of claim  19 , wherein the transparent substrate is a glassy carbon substrate. 
     
     
         4 . The method of claim  19 , wherein the nanostructured material has a formula ATiO 3-x , wherein:
 A is at least one metal selected from the group consisting of Ba, Co, Ni, Pb, Zn, Sr, and La, and 0<x<3.   
     
     
         5 . The method of claim  19 , wherein the nanostructured material has a formula CoTiO 3-x , wherein 0<x<3. 
     
     
         6 . The method of claim  19 , wherein the electrode has an overpotential of 0.2 to 0.5 volts (V) in an acidic medium at a current density of 5 to 20 milliamperes per square centimeter (mA/cm 2 ). 
     
     
         7 . The method of claim  19 , wherein the electrode has a double layer capacitance of 200 to 280 microfarads per square centimeter (μF/cm 2 ) in an acidic medium at an overpotential of 0.352 V RHE . 
     
     
         8 . The method of claim  19 , wherein the electrode has an active surface area of 4 to 10 square centimeters (cm 2 ) in an acidic medium at an overpotential of 0.352 V RHE . 
     
     
         9 . The method of claim  19 , wherein the electrode has a Tafel slope of 80 to 110 millivolts per decade (mV/decade) in an acidic medium at a scan rate of 5 to 20 millivolts per second (mV/s). 
     
     
         10 - 18 . (canceled) 
     
     
         19 . A method for electrochemical water splitting, comprising:
 applying a potential between a working electrode and a counter electrode in an electrochemical cell containing an electrolyte to form hydrogen and oxygen;   wherein the working electrode comprises an electrode having a transparent substrate, and a layer of a nanostructured material at least partially covering a surface of the transparent substrate;   wherein the nanostructured material comprises defective perovskite nanostructures (DPNSs) in the form of nanoplates having an average particle size in a range of 10 to 100 nanometers (nm), an interplanar spacing d(101) of the (101) plane in a range of 0.3 to 0.4 nm, and an interplanar spacing d(104) of the (104) plane in a range of 0.2 to 0.3 nm, as determined by X-ray diffraction; and   wherein the electrolyte comprising an aqueous solution of an acid having a concentration of 0.001 to 3 molars (M).   
     
     
         20 . The method of  claim 19 , wherein the acid comprises at least one acid selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, boric acid, and citric acid.