Using Molecular Design to Control the Performance of Hydrogen-Producing Polymer-Brush-Modified Photocathodes.
Attachment of difluoroborylcobaloxime catalysts to a polymer-brush-modified GaP semiconductor allows improved hydrogen production levels and photoelectrochemical performance under aqueous acidic conditions (pH = 4.5) as compared to the performance of electrodes without catalyst treatment. The catalytic assembly used in this work incorporates a boron difluoride (BF2) capping group on the glyoximate ligand of the catalyst, a synthetic modification previously used to enhance the stability of nonsurface-attached complexes toward acid hydrolysis and to shift the cobalt reduction potentials of the complex to less negative, and thus technologically more relevant, values. The pH-dependent photoresponses of the cobaloxime- and difluoroborylcobaloxime- modified semiconductors are shown to be consistent with those from analogous studies using non-surface-attached cobaloxime catalysts as well as catalysts supported on conductive electrodes. Thus, this work illustrates the potential to control and optimize the properties of visible-light-absorbing semiconductors using polymeric overcoating techniques coupled with the principles of synthetic molecular design.
Diana
D
Cedeno
Alexandra
A
Krawicz
Peter
P
Doak
Min
M
Yu
□Kavli Energy NanoSciences Institute at Berkeley, Berkeley, California 94720, United States.
Jeffrey B
JB
Neaton
∇Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, United States.
Gary F
GF
Moore
artificial photosynthesis; interfaces; photoelectrochemistry; solar fuels