Semiconductor‐Based, Solar‐Driven Photochemical Cells for Fuel Generation from Carbon Dioxide in Aqueous Solutions

Abstract

There has been active interest to identify new methods to reduce CO into usable fuel sources. In this work, we demonstrate two types of photo-electrochemical cells (PECs) that photoreduce CO directly to formate in aqueous solutions both in the presence and absence of external bias or additional electron sources. The photocathodes were either a CuFeO /CuO electrode or a bilayer of CdTe on NiO, whereas the photoanode was a bilayer of NiO on CdS. The PECs were characterized by using both electrochemistry and spectroscopy, and the products formed from CO reduction were characterized and quantified by using H NMR spectroscopy and ESI-MS. In addition, an organohydride catalyst was tested in conjunction with the PECs, which not only showed a significant gain of 85 times in CO reduction (27 μm formate without the catalyst, 2.3 mm formate with it) compared to the NiO/CdTe photocathode system but could also generate methanol under an external bias (10 μm).

Facilitating hole transfer on electrochemically synthesized p-type CuAlO2 films for efficient solar hydrogen production from water

“…3,17 However, they oen suffer from low efficiency, a complicated synthetic process, the use of expensive components, non-scalability, and low durability. Cu(I)-based delafossite materials are unique in terms of their structure (Cu I M III O 2 type, where M ¼ Fe, [18][19][20][21] Rh, 22 Al, 23,24 Ga, 25 etc. ); various bandgap (E g ) energies (1.2-3.0 eV); high conduction band (E cb ) level, which is sufficient for H 2 production and CO 2 reduction; and relative stability in aqueous solutions compared to other p-type III-V and II-VI materials.…”

DNA for Assembly and Charge Transport Photocatalytic Reduction of CO2

“…For testing the activity of each semiconductor nanocrystal, nanomolar solutions of either TiO 2 , CdS, or Au@CdS were mixed with an excess of ascorbic acid (90 × 10 −3 m ) and Rh*Cp(bpy) 2 (H 2 O) 2 (0.32 × 10 −3 m ) in phosphate buffer (pH 7) and degassed first for 1 h with Ar followed by a 1 h purge with CO 2 . The sealed solutions were next photoirradiated using a solar simulator (1 sun) for 11 h after which the products formed were characterized by 1 H NMR . As shown in Figure A, TiO 2 nanoparticles conjugated either with amine‐(PEG) 6 ‐azide or DNA showed as expected, little to no ability to reduce CO 2 to any measurable degree.…”

Photoelectrochemical CO2 Reduction via Cu2O/CuFeO2 Hierarchical nanorods photocatalyst

“…However, they were produced in film form by electrodeposition or dip coating and suffered from a low current density. [4,[31][32][33][34] Furthermore, studies on Cu 2 O/CuFeO 2 hierarchical photocatalysts have not yet been reported because of the difficulty in fabricating nanostructures suitable for photoelectrodes while simultaneously controlling the phase of Cu 2 O and CuFeO 2 , which is a ternary system. Here, we designed a Cu 2 O/CuFeO 2 hierarchical nanorod structure through thermodynamic considerations of oxygen partial pressure and temperature, and we successfully fabricated photocathodes via a simple fabrication process in which Fe 2 O 3 formed on nanostructured CuO through a spray pyrolysis method.…”

“…According to several previous studies, CuFeO 2 /CuO composites have been fabricated as photocatalysts. However, they were produced in film form by electrodeposition or dip coating and suffered from a low current density . Furthermore, studies on Cu 2 O/CuFeO 2 hierarchical photocatalysts have not yet been reported because of the difficulty in fabricating nanostructures suitable for photoelectrodes while simultaneously controlling the phase of Cu 2 O and CuFeO 2 , which is a ternary system.…”