Homojunction is a viable alternative strategy to realize excellent charge separation for enhancing photoelectrocatalytic performance. However, the feasible regulation of the homojunction interface remains challenging. Herein, a ZnO n-p homojunction with the piezotronic effect is constructed via an solvothermal method for enhancing photoelectrocatalytic activity. ZnO nanorods are transformed from n-type to p-type ZnO nanoparticles with zinc vacancies, leading to the n-p homojunction. The optimal NPZ-36 exhibits a superior photocurrent density of 1.56 mA/cm at 1.23 V RHE and a high incident photon to current conversion efficiency of 75 % at 360 nm. Impressively, with the merits of inherent piezoelectric and photocatalytic properties of wurtzite ZnO, the piezoelectric-enhanced photoelectrochemical activity originates from the simultaneous promotion of bulk charge transfer and interfacial charge separation in ZnO n-p homojunction. The photocurrent density of NPZ-36–900 can reach to 2.02 mA/cm under the stirring rate of 900 rpm, which is 2.1 times higher than that of pure ZnO photoanode.

中文翻译：

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通过金属/氧缺陷调制制备压电ZnO p-n同质结以实现高效光电催化


同质结是实现优异电荷分离以增强光电催化性能的可行替代策略。然而，同质结界面的可行调控仍然具有挑战性。在此，通过溶剂热方法构建了具有压电效应的ZnO n-p同质结，以增强光电催化活性。 ZnO 纳米棒从带有锌空位的 n 型 ZnO 纳米颗粒转变为 p 型 ZnO 纳米颗粒，形成 n-p 同质结。最佳 NPZ-36 在 1.23 V RHE 下表现出 1.56 mA/cm 的优异光电流密度，在 360 nm 下具有 75% 的高入射光子到电流转换效率。令人印象深刻的是，凭借纤锌矿ZnO固有的压电和光催化性能的优点，压电增强的光电化学活性源于ZnO n-p同质结中体电荷转移和界面电荷分离的同时促进。在900rpm的搅拌速率下，NPZ-36–900的光电流密度可以达到2.02mA/cm，是纯ZnO光阳极的2.1倍。