Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544-5263, USA.
Phys Chem Chem Phys. 2011 Oct 6;13(37):16644-54. doi: 10.1039/c1cp22128k. Epub 2011 Aug 19.
The positions of electronic band edges are one important metric for determining a material's capability to function in a solar energy conversion device that produces fuels from sunlight. In particular, the position of the valence band maximum (conduction band minimum) must lie lower (higher) in energy than the oxidation (reduction) reaction free energy in order for these reactions to be thermodynamically favorable. We present first principles quantum mechanics calculations of the band edge positions in five transition metal oxides and discuss the feasibility of using these materials in photoelectrochemical cells that produce fuels, including hydrogen, methane, methanol, and formic acid. The band gap center is determined within the framework of DFT+U theory. The valence band maximum (conduction band minimum) is found by subtracting (adding) half of the quasiparticle gap obtained from a non-self-consistent GW calculation. The calculations are validated against experimental data where possible; results for several materials including manganese(ii) oxide, iron(ii) oxide, iron(iii) oxide, copper(i) oxide and nickel(ii) oxide are presented.
能带边缘的位置是衡量材料在太阳能转换设备中性能的一个重要指标，该设备可利用阳光生产燃料。特别是，价带顶（导带底）的位置的能量必须低于（高于）氧化（还原）反应自由能，才能使这些反应在热力学上有利。我们提出了五种过渡金属氧化物的能带边缘位置的第一性原理量子力学计算，并讨论了这些材料在光电化学电池中的可行性，这些电池可生产燃料，包括氢气、甲烷、甲醇和甲酸。带隙中心是在 DFT+U 理论框架内确定的。价带顶（导带底）是通过从非自洽 GW 计算中减去（加上）准粒子间隙的一半来找到的。在可能的情况下，我们对计算结果进行了实验数据的验证；给出了包括二氧化锰、氧化亚铁、三氧化二铁、氧化亚铜和氧化镍在内的几种材料的结果。
