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Construction of Ultrathin S-Scheme Heterojunctions of Single Ni Atom Immobilized Ti-MOF and BiVO4 for CO2 Photoconversion of nearly 100% to CO by Pure Water
Advanced Materials ( IF 27.4 ) Pub Date : 2022-08-19 , DOI: 10.1002/adma.202205303
Lina Zhao 1 , Ji Bian 1 , Xianfa Zhang 1 , Linlu Bai 1 , Linyao Xu 1 , Yang Qu 1 , Zhijun Li 1 , Yuxin Li 1 , Liqiang Jing 1
Affiliation  

To rationally design single-atom metal–organic framework (MOF)-involving photocatalysts remains an ongoing challenge for efficient CO2 conversion. Here, cuppy microstructures, consisting of a Ti(IV)-oxo node and three linked carboxylic moieties, in the single-coordination-layer Ti2(H2dobdc)3 MOF (NTU-9) are exploited to immobilize abundant single Ni(II) sites (Ni@MOF). The coupling of Ni@MOF with BiVO4 (BVO) nanosheets by H-bonding-induced assembly process obtains wide-spectrum 2D heterojunctions. The optimal heterojunction exhibits competitive performance and enables around 66-fold CO2 conversion of that for BVO nanoparticles by pure water, with nearly 100% CO selectivity. The exceptional photoactivity is attributed to favorable S-scheme charge transfer from BVO to MOF then to single Ni(II) sites. Noteworthily, single Ni(II) sites anchored by the Ti(IV)-oxo node and vicinal carboxylic moieties serving as a unique local microenvironment (LME) are found to synergistically catalyze CO2 conversion. Specifically, the hydroxyl groups of carboxylic moieties can form H-bonds with CO2 to promote its adsorption on single Ni(II) sites, and also can provide accessible protons to facilitate H-assisted CO2 reduction. Moreover, the CO desorption and subsequent CO2 adsorption on single Ni(II) sites with LME is proved to be thermodynamically favored, and hence dominates the high CO selectivity. This work highlights the significance of modulating the LME of single atoms to rationally design photocatalysts for realizing carbon neutralization.

中文翻译:

单镍原子固定化 Ti-MOF 和 BiVO4 超薄 S 型异质结的构建,用于纯水将近 100% 的 CO2 光转化为 CO

合理设计涉及单原子金属有机骨架(MOF)的光催化剂仍然是高效 CO 2转化的持续挑战。在这里,在单配位层 Ti 2 (H 2 dobdc) 3 MOF (NTU-9) 中,由 Ti(IV)-oxo 节点和三个连接的羧基组成的杯状微结构被用来固定丰富的单 Ni( II)网站(Ni@MOF)。通过氢键诱导组装工艺将 Ni@MOF 与 BiVO 4 (BVO) 纳米片耦合获得广谱二维异质结。最佳异质结表现出具有竞争力的性能,并能实现约 66 倍的 CO 2用纯水转化 BVO 纳米颗粒,CO 选择性接近 100%。优异的光活性归因于从 BVO 到 MOF 再到单个 Ni(II) 位点的有利 S 型电荷转移。值得注意的是,发现由 Ti(IV)-oxo 节点锚定的单个 Ni(II) 位点和作为独特局部微环境 (LME) 的连位羧基部分可协同催化 CO 2转化。具体而言,羧基部分的羟基可以与CO 2形成H键以促进其在单个Ni(II)位点上的吸附,并且还可以提供可接近的质子以促进H辅助CO 2还原。此外,CO 解吸和随后的 CO 2事实证明,用 LME 在单个 Ni(II) 位点上的吸附在热力学上是有利的,因此决定了高 CO 选择性。这项工作突出了调节单原子的 LME 对合理设计实现碳中和的光催化剂的重要性。
更新日期:2022-08-19
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