Hong Inju, Chen Yi-An, Hsu Yung-Jung, Yong Kijung
Surface Chemistry Laboratory of Electronic Materials (SCHEMA), Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea.
Research Center for Carbon-zero Green Ammonia Cycling, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea.
ACS Appl Mater Interfaces. 2021 Nov 10;13(44):52670-52680. doi: 10.1021/acsami.1c15883. Epub 2021 Nov 1.
-scheme heterojunctions are fundamentally promising yet practically appealing for photocatalytic hydrogen (H) production owing to the enhanced redox power, spatial separation of charge carriers, and broad-spectrum solar light harvesting. The charge-transfer dynamics at -scheme heterojunctions can be accelerated by inserting charge-transfer mediators at the heterojunction interfaces. In this study, we introduce Au nanoparticle mediators in the -scheme WO/g-CN heterostructure, which enables an improved H production rate of 3465 μmol/g·h compared with the direct -scheme WO/g-CN (1785 μmol/g·h) under 1 sun irradiation. The apparent quantum yields of H production with WO/Au/g-CN are 3.9% and 9.3% at 420 and 1200 nm, respectively. The improved photocatalytic H production activity of WO/Au/g-CN is attributable to the triple-channel charge-transfer mechanism: channel I─-scheme charge transfer facilitates charge separation and increased redox power of the photoexcited electrons; channels II and III─the localized surface plasmon resonances from Au (channel II) and WO (channel III) enable light harvesting extension from visible to near-infrared wavelengths.
由于氧化还原能力增强、电荷载流子的空间分离以及宽光谱太阳光捕获，Z型异质结在光催化产氢方面从根本上具有前景且在实际应用中具有吸引力。通过在异质结界面插入电荷转移介质，可以加速Z型异质结处的电荷转移动力学。在本研究中，我们在Z型WO₃/g-C₃N₄异质结构中引入金纳米颗粒介质，这使得在1个太阳光照下，与直接的Z型WO₃/g-C₃N₄（1785 μmol/g·h）相比，产氢速率提高到3465 μmol/g·h。WO₃/Au/g-C₃N₄产氢的表观量子产率在420和1200 nm处分别为3.9%和9.3%。WO₃/Au/g-C₃N₄光催化产氢活性的提高归因于三通道电荷转移机制：通道I─Z型电荷转移促进电荷分离并增加光激发电子的氧化还原能力；通道II和III─来自金（通道II）和WO₃（通道III）的局域表面等离子体共振使光捕获范围从可见光扩展到近红外波长。
