Platinum@Hexaniobate Nanopeapods: A Directed Photocatalytic Architecture for Dye-Sensitized Semiconductor H₂ Production under Visible Light Irradiation

Abstract

Platinum@hexaniobate nanopeapods (Pt@HNB NPPs) are a nanocomposite photocatalyst that was selectively engineered to increase the efficiency of hydrogen production from visible light photolysis. Pt@HNB NPPs consist of linear arrays of high surface area Pt nanocubes encapsulated within scrolled sheets of the semiconductor H x K 4−x Nb 6 O 17 and were synthesized in high yield via a facile one-pot microwave heating method that is fast, reproducible, and more easily scalable than multi-step approaches required by many other state-of-the-art catalysts. The Pt@HNB NPPs' unique 3D architecture enables physical separation of the Pt catalysts from competing surface reactions, promoting electron efficient delivery to the isolated reduction environment along directed charge transport pathways that kinetically prohibit recombination reactions. Pt@HNB NPPs' catalytic activity was assessed in direct comparison to representative state-of-the-art Pt/semiconductor nanocomposites (extPt-HNB NScs) and unsupported Pt nanocubes. Photolysis under similar conditions exhibited superior H 2 production by the Pt@HNB NPPs, which exceeded other catalyst H 2 yields (μmol) by a factor of 10. Turnover number and apparent quantum yield values showed similar dramatic increases over the other catalysts. Overall, the results clearly demonstrate that Pt@HNB NPPs represent a unique, intricate nanoarchitecture among state-of-the-art heterogeneous catalysts, offering obvious benefits as a new architectural pathway toward efficient, versatile, and scalable hydrogen energy production. Potential factors behind the Pt@HNB NPPs' superior performance are discussed below, as are the impacts of systematic variation of photolysis parameters and the use of a non-aqueous reductive quenching photosystem.

Interlayer modification and single-layer exfoliation of the Ruddlesden–Popper perovskite oxynitride K2LaTa2O6N to improve photocatalytic H2 evolution activity

“…Recently, dye-sensitized niobate nanosheets and nanoscrolls have been reported to function as good H 2 evolution photocatalysts capable of functioning under visible light but the low stability of the dye component needs to be addressed. 14,44,45 In contrast to such dye-sensitized oxide systems, oxynitride nanosheets that are already capable of absorbing visible light do not require an additional photosensitizer dye. Thus, the results of this work demonstrate the signicant potential of twodimensional LaTa 2 O 6 N 2− sheets with regard to the construction of visible-light-driven water splitting systems.…”

Cost-Effective and Highly Efficient Manganese-Doped MoS2 Nanosheets as Visible-Light-Driven Photocatalysts for Wastewater Treatment

“…Due to their exceptional energy harvesting and environmental remedies applications, visible-light-driven photocatalysts have been the subject of extensive research. Engineered nanostructures driven by visible light have shown the ability to capture light under the illumination of visible light. − Photocatalytic materials should be catalytically active to visible light, which can significantly absorb the visible spectrum from sunlight, for more cutting-edge and practical applications . After the fantastic discovery of water splitting by Fujishima in 1972, semiconductor-based photocatalysts have been proven one of the ideal choices for degrading organic contaminants utilizing light irradiation .…”