Kumar Pradhan Sibun, Bariki Ranjit, Kumar Nayak Swagat, Panda Saumyaranjan, Kanungo Shubham, Mishra B G
Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India.
Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India.
J Colloid Interface Sci. 2024 Jan 15;654(Pt A):523-538. doi: 10.1016/j.jcis.2023.10.062. Epub 2023 Oct 14.
Rational design of novel conjugated step-scheme (S-scheme) multijunction heterostructure with synergistic charge channelization, superior light harvesting efficiency and strong redox ability is a pioneering approach to mimic natural photosynthesis process. Herein, a mild cetyltrimethyl ammoniumbromide (CTAB) assisted one pot reflux synthesis route is designed for in situ integration of metal organic framework (MOF)-derived NiFeO with tetragonal-BiVO (t-BiVO) and γ-BiMoO to prepare NiFeO/t-BiVO/BiMoO (NFO/BVO/BMO) ternary composites. Morphologically, fine dispersion of NiFeO (NFO) quantum dots over γ-BiMoO (BMO) and t-BiVO (BVO) nanoplates yielded three types of microscopic heterojunctions among BMO-BVO, BVO-NFO and BMO-NFO phases. The ternary composites displayed important physicochemical attributes including high surface area, strong optical absorption, superior charge mobility and higher excited state lifetime which accounted for its improved photocatalytic activity towards ciprofloxacin degradation (>99% in 90 min) and H evolution (1.11 mmolhg, photon conversion efficiency 18.5%). Kinetics study revealed 12-55 fold higher ciprofloxacin photodegradation activity and 31-41 times higher H evolution rate for the ternary composite in comparison to the pure semiconductors. A conjugated S-scheme charge transfer mechanism has been deduced from comprehensive band position analysis and radical trapping study to explain the enhanced photocatalytic activity. This work for the first time demonstrated the rational construction of conjugated S-scheme heterostructures with potential application in water remediation and green H production.
合理设计具有协同电荷通道化、卓越光捕获效率和强氧化还原能力的新型共轭阶梯式（S 型）多结异质结构是模拟自然光合作用过程的一种开创性方法。在此，设计了一种温和的十六烷基三甲基溴化铵（CTAB）辅助一锅回流合成路线，用于将金属有机框架（MOF）衍生的 NiFeO 与四方相 BiVO（t-BiVO）和 γ-BiMoO 原位整合，以制备 NiFeO/t-BiVO/BiMoO（NFO/BVO/BMO）三元复合材料。从形态上看，NiFeO（NFO）量子点在 γ-BiMoO（BMO）和 t-BiVO（BVO）纳米片上的精细分散在 BMO-BVO、BVO-NFO 和 BMO-NFO 相之间产生了三种类型的微观异质结。该三元复合材料表现出重要的物理化学特性，包括高比表面积（高表面积）、强光学吸收、卓越的电荷迁移率和更长的激发态寿命，这解释了其对环丙沙星降解（90 分钟内>99%）和析氢（1.11 mmol h g，光子转换效率 18.5%）的光催化活性提高。动力学研究表明，与纯半导体相比，该三元复合材料的环丙沙星光降解活性高 12 - 55 倍，析氢速率高 31 - 41 倍。通过综合能带位置分析和自由基捕获研究推导了一种共轭 S 型电荷转移机制，以解释增强的光催化活性。这项工作首次展示了共轭 S 型异质结构的合理构建，在水修复和绿色制氢方面具有潜在应用。
