Incorporation of Mo and W into nanostructured BiVO4 films for efficient photoelectrochemical water oxidation
Incorporation of Mo and W into nanostructured BiVO4 films for efficient photoelectrochemical water oxidation
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DOI：
10.1039/c2cp40807d
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发表时间：
2012-01-01
影响因子：
3.3
通讯作者：
Mullins, C. Buddie
中科院分区：
文献类型：
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作者：
Berglund, Sean P.;Rettie, Alexander J. E.;Mullins, C. Buddie
多孔的，纳米结构的BiVO 4薄膜与Mo和W通过在真空中同时蒸发Bi，V，Mo和W，然后在空气中氧化而结合。调整合成参数如Bi：V：Mo：W原子比和沉积角度以优化用于光电化学（PEC）水氧化的膜。用Bi：V：Mo：W原子比为46：46：6：2（6%Mo，2%W）合成的膜表现出最好的PEC性能，其光电流密度比纯BiVO 4高10倍，并且大于先前报道的含Mo和W的BiVO 4。该膜由不规则表面结构下的定向纳米柱状层组成。背面照明利用从不规则表面结构散射的光，导致比正面照明高30-45%的光电流密度。为了提高水氧化的动力学Pt是光沉积到表面上的6%Mo，2%W BiVO 4膜作为电催化剂。对于450 nm光，这些膜在1.1 V vs. RHE下实现37%的量子效率，在1.6 V vs. RHE下实现50%的量子效率。
Porous, nanostructured BiVO4 films are incorporated with Mo and W by simultaneous evaporation of Bi, V, Mo, and W in vacuum followed by oxidation in air. Synthesis parameters such as the Bi : V: Mo : W atomic ratio and deposition angle are adjusted to optimize the films for photoelectrochemical (PEC) water oxidation. Films synthesized with a Bi : V: Mo: W atomic ratio of 46 : 46 : 6 : 2 (6% Mo, 2% W) demonstrate the best PEC performance with photocurrent densities 10 times higher than for pure BiVO4 and greater than previously reported for Mo and W containing BiVO4. The films consist of a directional, nanocolumnar layer beneath an irregular surface structure. Backside illumination utilizes light scattering off the irregular surface structure resulting in 30-45% higher photocurrent densities than for frontside illumination. To improve the kinetics for water oxidation Pt is photo-deposited onto the surface of the 6% Mo, 2% W BiVO4 films as an electrocatalyst. These films achieve quantum efficiencies of 37% at 1.1 V vs. RHE and 50% at 1.6 V vs. RHE for 450 nm light.