Photoelectrochemical cell for carbon dioxide conversion

Abstract

the present disclosure relates to photoelectrochemical cells and methods for using such for reduction of carbon dioxide and oxidation of water. In one aspect, the disclosure provides a method of electrochemically reducing carbon dioxide in an electrochemical cell, comprising contacting the carbon dioxide with at least one transition metal dichalcogenide in the electrochemical cell and at least one helper catalyst and applying a potential to the electrochemical cell.

We claim: 
     
         1 . A method of electrochemically reducing carbon dioxide and oxidizing water in an electrochemical device, the method comprising providing an electrochemical device, the device including a first and second compartment and at least one photovoltaic cell, wherein
 the first compartment includes
 a cathode in electrical contact with at least one transition metal dichalcogenide, 
 a first electrolyte, and 
 carbon dioxide, carbonic acid, or a carbonic acid salt; 
   the second compartment includes
 an anode in electrical contact with at least one water oxidizing catalyst, 
 a second electrolyte, and 
 water; 
   the at least one photovoltaic cell is in electrical contact with the anode and the cathode; and   the first compartment is in ionic contact with the second compartment; and   exposing the photovoltaic cell to light irradiation sufficient to create a potential difference between the anode and the cathode sufficient to reduce carbon dioxide at the cathode and to oxidize water at the cathode.   
     
     
         2 . A method according to  claim 1 , wherein the transition metal dichalcogenide is selected from the group consisting of TiS 2 , TiSe 2 , MoS 2 , MoSe 2 , WS 2  and WSe 2 . 
     
     
         3 . A method according to  claim 1 , wherein the transition metal dichalcogenide is MoS 2 . 
     
     
         4 . A method according to  claim 1 , wherein the transition metal dichalcogenide is in nanoparticle form, wherein the transition metal dichalcogenide nanoparticles have an average size between about 1 nm and about 400 nm. 
     
     
         5 . A method according to  claim 1 , wherein the transition metal dichalcogenide is in nanoflake, nanosheet, or nanoribbon form, wherein the transition metal dichalcogenide nanoflakes, nanosheets, or nanoribbons have an average size between about 1 nm and about 400 nm. 
     
     
         6 . A method according to  claim 1 , wherein the first electrolyte comprises at least one helper catalyst. 
     
     
         7 . A method according  claim 6 , wherein the helper catalyst is an imidazolium, pyridinium, pyrrolidinium, phosphonium, ammonium, choline, sulfonium, prolinate, or methioninate salt. 
     
     
         8 . A method according to  claim 6 , wherein wherein the helper catalyst is an imidazolium, pyridinium, pyrrolidinium, phosphonium, ammonium, choline or sulfonium salt having a counterion selected from the group consisting of C 1 -C 5  alkylsulfate, tosylate, methanesulfonate, bis(trifluoromethylsulfonyl)imide, hexafluorophosphate, tetrafluoroborate, triflate, halide, carbamate, and sulfamate. 
     
     
         9 . A method according to  claim 6 , wherein in the first electrolyte the helper catalyst is present in the aqueous solution in a concentration within the range of about 25 vol. % to about 75 vol. %. 
     
     
         10 . A method according to  claim 1 , wherein the first electrolyte is an aqueous solution. 
     
     
         11 . A method according to  claim 1 , wherein reducing carbon dioxide provides CO or a mixture of CO and H 2 . 
     
     
         12 . A method according to  claim 1 , wherein the reduction of carbon dioxide is initiated at an overpotential of less than about 100 mV, and the reduction of the carbon dioxide has a Faradaic efficiency of at least 70%. 
     
     
         13 . A method according to  claim 1 , wherein the second electrolyte and the water comprise an aqueous solution. 
     
     
         14 . A method according to  claim 1 , wherein the water oxidizing catalyst comprises a cobalt-comprising film disposed on the anode. 
     
     
         15 . A method according to  claim 1 , wherein oxidizing water produces a mixture of O 2  and H + . 
     
     
         16 . A method according to  claim 1 , wherein the first compartment is in ionic contact with the second compartment through a proton-conductive membrane. 
     
     
         17 . A method according to  claim 1 , wherein the cathode and the anode are disposed on opposite surfaces of the photovoltaic cell such that the photovoltaic cell is sandwiched between the cathode and the anode. 
     
     
         18 . An electrochemical device having a first and second compartment and at least one photovoltaic cell, wherein
 the first compartment includes
 a cathode in electrical contact with at least one transition metal dichalcogenide, 
 a first electrolyte, and 
 carbon dioxide, carbonic acid, or a carbonic acid salt; 
   the second compartment includes
 an anode in electrical contact with at least one water oxidizing catalyst, 
 a second electrolyte, and 
 water; 
   the at least one photovoltaic cell is in electrical contact with the anode and the cathode; and   the first compartment is in ionic contact with the second compartment.   
     
     
         19 . A method of electrochemically reducing carbon dioxide in an electrochemical cell, comprising contacting the carbon dioxide with at least one transition metal dichalcogenide in the electrochemical cell and at least one helper catalyst and applying a potential to the electrochemical cell, wherein the at least one transition metal dichalcogenide is MoSe 2 , MoSe 2 , WSe 2  or WS 2 . 
     
     
         20 . A method of electrochemically reducing carbon dioxide according to  claim 19  comprising providing an electrochemical cell having
 a cathode in contact with at least one transition metal dichalcogenide, and 
 an electrolyte comprising at least one helper catalyst in contact with the cathode and the at least one transition metal dichalcogenide, 
 wherein the at least one transition metal dichalcogenide is MoSe 2 , MoSe 2 , WSe 2  or WS 2 ; 
 providing carbon dioxide to the electrochemical cell; and 
 applying a potential to the electrochemical cell.