ZnO nanowires have been proposed as potential photo-anode materials for photo-electrochemical water splitting due to their low toxicity, simple synthesis and easy modification routes. However, ZnO suffers from low PEC activity and photo-corrosion eff ;ects, and therefore, application of ZnO nanowires in PEC water splitting still awaits development of effective design and synthesis strategies to improve its PEC efficiencies to commercially viable levels. Here, we present ab initio Density Functional Theory calculations considering 3d transition metal doping as a potential route towards attainment of ZnO nanowires with superior PEC activity. Our results show that the stability of 3d transition metal dopants in ZnO NWs is dependent on the d character of the transition metal dopant as well as their concentration and doping site, with most transition metal atoms being energetically most favorable at the Zn substitutional site both in O-rich and Zn-rich conditions considered. Specifically, we find all 3d transition metal dopants in ZnO NW under O-rich conditions as well as Sc, Ti and V under Zn-rich conditions have negative formation energies at the considered dopant concentrations of 1−6 atm. %, indicating that these dopants can readily be incorporated into ZnO NWs at thermodynamic equilibrium conditions. The electronic properties of Ti and V at 2% and 4% dopant concentration, respectively, yield a staggered band-structure configuration, while Sc, Cr, Mn, Co, Ni, and Cu dopants in ZnO NWs induce band-edge states. In addition, 3d TM dopants induces significant red-shift of the absorption edge of ZnO NW due to reduction in band gap, and are projected to improve visual light harvesting capabilities. Finally, the band alignment relative to the redox potential of water revealed that the valence band maximum of Sc, V, Ni and Cu doped ZnO NWs remains strongly positive above the oxidation potential of O₂/H₂O, while their reduction potential remain negative below the reduction potential of H⁺/H_2, favouring PEC applications.

ZnO纳米线具有毒性低，合成简单，修饰途径简单等优点，已被提出作为光电化学水分解的潜在光阳极材料。但是，ZnO具有低的PEC活性和光腐蚀作用，因此，将ZnO纳米线用于PEC水分解中仍需等待有效的设计和合成策略的发展，以将其PEC效率提高到商业上可行的水平。在这里，我们提出了从头算密度泛函理论的计算，其中考虑了3d过渡金属的掺杂，这是实现具有优异PEC活性的ZnO纳米线的潜在途径。我们的结果表明，ZnO NWs中3d过渡金属掺杂剂的稳定性取决于d过渡金属掺杂剂的特性及其浓度和掺杂位点，无论是在富含O还是富含Zn的条件下，大多数过渡金属原子在Zn取代位点上在能量上最有利。具体而言，我们发现在富氧条件下ZnO NW中的所有3 d过渡金属掺杂剂，以及在富锌条件下的Sc，Ti和V在所考虑的掺杂剂浓度为1-6 atm时都具有负形成能。％，表明这些掺杂剂可以在热力学平衡条件下容易地掺入ZnO NW中。掺杂浓度为2％和4％的Ti和V的电子特性分别产生交错的能带结构，而ZnO NW中的Sc，Cr，Mn，Co，Ni和Cu掺杂剂则产生了带边缘态。此外，3天由于带隙的减小，TM掺杂剂会引起ZnO NW吸收边缘的明显红移，并有望改善可见光的收集能力。最后，相对于水的氧化还原电位的能带排列表明，Sc，V，Ni和Cu掺杂的ZnO NW的价带最大值在O ₂ / H ₂ O的氧化电位以上仍保持强正电，而其还原电势仍为负。低于H ⁺ / H ₂的还原电位_，有利于PEC应用。