Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
J Am Chem Soc. 2010 Mar 31;132(12):4202-7. doi: 10.1021/ja908730h.
A cobalt-phosphate water oxidation catalyst ("Co-Pi") has been electrodeposited onto mesostructured alpha-Fe(2)O(3) photoanodes. The photoelectrochemical properties of the resulting composite photoanodes were optimized for solar water oxidation under frontside illumination in pH 8 electrolytes. A kinetic bottleneck limiting the performance of such photoanodes was identified and shown to be largely overcome by more sparse deposition of Co-Pi onto the alpha-Fe(2)O(3). Relative to alpha-Fe(2)O(3) photoanodes, a sustained 5-fold enhancement in the photocurrent density and O(2) evolution rate was observed at +1.0 V vs RHE with the Co-Pi/alpha-Fe(2)O(3) composite photoanodes. These results demonstrate that integration of this promising water oxidation catalyst with a photon-absorbing substrate can provide a substantial reduction in the external power needed to drive the catalyst's electrolysis chemistry.
一种钴-磷酸盐水氧化催化剂（“Co-Pi”）已被电沉积在介孔α-Fe(2)O(3)光阳极上。优化了所得复合光阳极在 pH 8 电解质中正面照明下进行太阳能水氧化的光电化学性能。确定了限制这种光阳极性能的动力学瓶颈，并通过更稀疏地沉积 Co-Pi 到α-Fe(2)O(3)上，在很大程度上克服了该瓶颈。与α-Fe(2)O(3)光阳极相比，在 Co-Pi/α-Fe(2)O(3)复合光阳极上，在+1.0 V 相对于 RHE 时观察到光电流密度和 O(2)演化率持续提高 5 倍。这些结果表明，将这种有前途的水氧化催化剂与光子吸收衬底集成，可以大大减少驱动催化剂电解化学所需的外部功率。
