Semiconductors and metals can form an Ohmic contact with an electric field pointing to the metal, or a Schottky contact with an electric field pointing to the semiconductor. If these two types of heterojunctions are constructed on a single nanoparticle, the two electric fields may cause a synergistic effect and increase the separation rate of the photogenerated electrons and holes. Metal Ni and Ag nanoparticles were successively loaded on the graphitic carbon nitride (g-C3 N4 ) surface by precipitation and photoreduction in the hope of forming hybrid heterojunctions on single nanoparticles. TEM/high-resolution TEM images showed that Ag and Ni were loaded on different locations on C3 N4 , which indicated that during the photoreduction reaction Ag+ obtained electrons from C3 N4 in the reduction reaction, whereas oxidation reactions proceeded on Ni nanoparticles. Photocatalytic hydrogen production experiments showed that C3 N4 -based hybrid heterojunctions can greatly improve the photocatalytic activity of materials. The possible reason is that two heterojunctions could form a long-range electric field similar to the p-i-n structure in semiconductors. Most of the photogenerated carriers were generated and then separated in this electric field, thereby increasing the separation rate of electrons and holes. This further improved the photocatalytic activity of C3 N4 .

中文翻译：

---

基于C3 N4的杂化异质结的设计，以增强光催化氢的产生活性。

半导体和金属可以与指向金属的电场形成欧姆接触，或者与指向半导体的电场形成肖特基接触。如果将这两种类型的异质结构建在单个纳米粒子上，则这两个电场可能会产生协同效应，并增加光生电子和空穴的分离率。通过沉淀和光还原将金属Ni和Ag纳米颗粒依次负载在石墨氮化碳（g-C3 N4）表面上，希望在单个纳米颗粒上形成杂化异质结。TEM /高分辨率TEM图像显示，Ag和Ni负载在C3 N4的不同位置，这表明在光还原反应过程中，Ag +在还原反应中从C3 N4获得了电子，而氧化反应在镍纳米粒子上进行。光催化制氢实验表明，基于C3 N4的杂化异质结可以大大提高材料的光催化活性。可能的原因是，两个异质结可能形成类似于半导体引脚结构的长距离电场。大部分光生载流子被生成，然后在该电场中分离，从而提高了电子和空穴的分离率。这进一步提高了C3N4的光催化活性。可能的原因是，两个异质结可能形成类似于半导体引脚结构的长距离电场。大部分光生载流子被生成，然后在该电场中分离，从而提高了电子和空穴的分离率。这进一步提高了C3N4的光催化活性。可能的原因是，两个异质结可能形成类似于半导体引脚结构的长距离电场。大部分光生载流子被生成，然后在该电场中分离，从而提高了电子和空穴的分离率。这进一步提高了C3N4的光催化活性。