The different morphologies of K-doped ZnO nanostructures were successfully synthesized by a facile one-step electrochemical method using control of the current density. Field emission electron microscope images showed various morphologies and aspect ratios due to change in the value of applied current densities. Photoluminescence and UV-visible spectrometers showed that change in current densities leads in different level of defects and band gap shifting. The photocurrent responses reveal that the photocurrent intensity increases as K-doped ZnO surface morphology tends to taper on the application of 0.5 mA cm⁻² current density. The maximum degradation rate of methylene blue was attained to be 99.3% within the 60 min using K-doped ZnO nanotapers which was much higher than the values found in previous studies. The highest photocatalytic H₂ evolution activities were obtained in the applied current density of 0.5 mA cm⁻² in comparison to other samples. These results indicate that doping and controllable morphology are effective and facile methods to improve the photocatalytic features of ZnO by boosting the absorption of light.

通过控制电流密度的简便的一步电化学方法成功地合成了K掺杂的ZnO纳米结构的不同形态。场发射电子显微镜图像显示由于施加的电流密度值的变化而产生的各种形态和纵横比。光致发光和紫外可见光谱仪表明，电流密度的变化导致不同程度的缺陷和带隙位移。光电流响应表明，在0.5 mA cm ^-2的应用下，随着K掺杂的ZnO表面形态趋于逐渐变细，光电流强度增加。当前密度。使用K掺杂的ZnO纳米锥在60分钟内，亚甲基蓝的最大降解率达到99.3％，远高于以前的研究结果。与其他样品相比，在0.5 mA cm ^-2的施加电流密度下获得了最高的光催化H ₂放出活性。这些结果表明，掺杂和可控形态是通过促进光吸收来改善ZnO的光催化特性的有效且简便的方法。