Query: Plasmonic nanoparticle-semiconductor composites for efficient solar water splitting

Candidate papers:

abstract: Photoelectrochemical (PEC) water splitting is a promising technology that uses light absorbing semiconductors to convert solar energy directly into a chemical fuel (i.e. hydrogen) PEC water splitting has the potential to become a key technology in achieving a sustainable society, if high solar to fuel energy conversion efficiencies are obtained with earth abundant materials. This review article discusses recent developments and discoveries in the mechanisms by which the localized surface plasmon resonance (LSPR) in metallic nanoparticles can increase or complement a neighbouring semiconductor in light absorption for catalytic water splitting applications. These mechanisms can mitigate the intrinsic optical limitations of semiconductors (e.g. metal oxides) for efficient solar water splitting. We identify four types of enhancement mechanisms in the recent literature: (i) light scattering, (ii) light concentration, (iii) hot electron injection (HEI) and (iv) plasmon induced resonance energy transfer (PIRET) (i) Light scattering and (ii) light concentration are light trapping mechanisms that can increase the absorption of light with energies above the semiconductor optical band edge. These two mechanisms are ideal to enhance the absorption of promising semiconductors with narrow bandgap energies that suffer from limited absorption coefficients and bulk charge recombination. On the other hand, (iii) HEI and the recently discovered (iv) PIRET are mechanisms that can enhance the absorption also below the semiconductor optical band edge. Therefore, HEI and PIRET have the potential to extend the light utilization to visible and near infrared wavelengths of semiconductors with excellent electrochemical properties, but with large bandgap energies. New techniques and theories that have been developed to elucidate the above mentioned plasmonic mechanisms are presented and discussed for their application in metal oxide photoelectrodes. Finally, other plasmonic and non plasmonic effects that do not increase the device absorption, but affect the electrochemical properties of the semiconductor (e.g. charge carrier transport) are also discussed, since a complete understanding of these phenomena is fundamental for the design of an efficient plasmonic NP semiconductor water splitting device.
author_names: Marco Valenti

Magnus P Jonsson

George Biskos

A Schmidt-ott

Wilson A Smith
title: Plasmonic nanoparticle semiconductor composites for efficient solar water splitting
year: 2016

abstract: Abstract We report the application of plasmonic Bi nanoparticles supported rGO/BiVO4 anode for photoelectrochemical (PEC) water splitting. Nearly, 2.5 times higher activity was observed for Bi rGO/BiVO4 composite than pristine BiVO4. Typical results indicated that Bi rGO/BiVO4 exhibits the highest current density of 6.05 mA/cm2 at 1.23 V, whereas Bi BiVO4 showed the current density of only 3.56 mA/cm2. This enhancement in PEC activity on introduction of Bi rGO is due to the surface plasmonic behavior of BiNPs, which improves the absorption of radiation thereby reduces the charge recombination. Further, the composite electrode showed good solar to hydrogen conversion efficiency, appreciable incident photon to current efficiency and low charge transfer resistance. Hence, Bi rGO/BiVO4 provides an opportunity to realize PEC water splitting.
author_names: Palyam Subramanyam

Tanmoy Khan

Gudipati Neeraja Sinha

Duvvuri Suryakala

Ch Subrahmanyam
title: Plasmonic Bi nanoparticle decorated BiVO4/rGO as an efficient photoanode for photoelectrochemical water splitting
year: 2020

abstract: Abstract Plasmonic metal nanoparticles containing photoanodes are known to exhibit stable photoelectrochemical (PEC) performance due to their optical and electronic properties. In this work, we report the application of plasmonic Bi nanoparticles supported over a g C3N4/Bi2S3 photoanode for PEC water splitting. Typical results indicated that g C3N4/Bi2S3/BiNPs ternary composite photoanode showed a high photo current density of 7.11 mA cm 2 at 1.23 V under solar irradiation, which was 5 and 10 times higher than g C3N4/Bi2S3 and g C3N4 photoanodes, respectively. Further, the composite electrode also demonstrated superior solar to hydrogen efficiency and long term stability. It was concluded that Bi nanoparticles play a major role in enhancing the PEC performance for hydrogen evolution reaction. Thus, g C3N4/Bi2S3/BiNPs has superior PEC performance and proved to work as an alternative to noble metal based photo electrodes for solar water splitting reactions.
author_names: Palyam Subramanyam

Bhagat Ram Meena

Duvvuri Suryakala

Melepurath Deepa

Ch Subrahmanyam
title: Plasmonic nanometal decorated photoanodes for efficient photoelectrochemical water splitting
year: 2020

abstract: We report plasmonic Bi metal and rGO decorated on BiVO4 using a simple single step synthesis technique followed by drop casting. Impressive five fold increment in activity is observed on BiVO4@Bi rGO composite compared to pristine BiVO4 under visible light irradiation. This enhancement in photoelectrochemical performance on the introduction of SPR effect of Bi NPs and high electrical conductivity of rGO is ascribed to inhibited charge recombination and enhanced charge injection. The composite BiVO4@Bi rGO exhibit a high photocurrent density of 4.21 mA cm 2 than BiVO4@ Bi electrode whose photocurrent density is 1.91 mA cm 2 at 1.23 V vs RHE. This indicates the synergistic effect of Bi NPs and rGO in the composite. Further, superior solar to hydrogen efficiency, appreciable IPCE and low charge transfer resistance are achieved for this composite. Details on this improved PEC activity of BiVO4@Bi rGO are marked in this work which can be adapted to make more efficient photoanodes.
author_names: Tanmoy Khan

Ch Subrahmanyam
title: Plasmonic Bi metal and rGO decorated on BiVO4 as an efficient photoanode for photoelectrochemical water splitting
year: 2019

abstract: This work exploits the ability of the spark discharge particle generator (SDG) to produce metallic nanoparticles (NPs) with control over the size, shape and composition, to unravel the plasmonic mechanisms by which NPs can enhance the photoelectrochemical performance of semiconductor photoanodes. Chapter 1 gives an overview of the SDG and the aerosol technology used in this thesis to synthesize the NPs. Chapter 2 summarizes the different aerosol NP immobilization techniques (both on solids and in liquids) and introduces for the first time an electrospray technique to efficiently capture neutral NPs in liquids. In chapter 3, an extensive literature review on plasmonic photoelectrocatalysis is given to introduce the plasmonic mechanisms that are experimentally studied in Chapter 4, 5, 6 and 7. Chapter 4 and 5 are dedicated to study the hot electron injection (HEI) mechanism by which plasmonic NPs create light induced "hot" charge carriers upon illumination that can drive photoelectrochemical reactions. Chapter 4 reveals that alloying Ag NPs with Au can be used to shift in a control way the absorption and utilization of light to longer wavelengths. However, due to the low interband energy of Au (i.e. 2.3 eV) compared to that of Ag (i.e. 3.6 eV) the alloy NPs exhibited more interband excitations when illuminated with visible light than pure Ag NPs. Such increase in interband excitations resulted in lower hot electron energies and HEI efficiencies in the alloy NPs than in pure Ag NPs. Chapter 5, reveals the HEI size dependency of Ag NPs. It is found that smaller NPs (l 10 nm) where the surface induced excitations are prominent result in higher HEI efficiencies, while for larger light absorbing NPs (in the range 10 25 nm) a maximum in the performance is found that corresponds well with the size of the Ag NP with the largest nearfield enhancement. Chapter 6, studies the ability of Ag NPs to concentrate and scatter light into thin film semiconductors to enhance their absorption. It is found that most of the solar energy absorbed by pure 15 nm Ag NPs is lost through heat dissipation. However, larger NPs preferentially scatter the incoming light to the neighbour 6 semiconductor, improving its absorption above their band gap energy. Finally, two configurations of plasmonic NP/semiconductor composites were studied to enhance the semiconductor absorption. In the first configuration the NPs were placed at the semiconductor electrolyte interface and in the second configuration, the NPs were embedded in the semiconductor at the back contact/semiconductor interface. It was found that an absorption enhancement at the semiconductor/electrolyte interface was better utilized due to the ability of the surface charge layer to efficiently separate the extra electron holes induced by the plasmonic NPs.
author_names: Marco Valenti
title: Spark Discharge as a Nanoparticle Source to Study Size Dependent Plasmonic Properties for Photo electrochemical Water Splitting
year: 2018

abstract: Abstract The rising demand for sustainable and efficient solar energy conversion strategies has triggered the development of a myriad of semiconductor based composite systems for photocatalytic water splitting. Plasmonic nanostructures recently emerged as a promising alternative to conventionally used photosensitizers (e.g. organic dyes) that complement semiconductors as they can uniquely harness the energy of visible photons through the excitation of the localized surface plasmon resonance (LSPR) Provided the solid foundation of the mechanisms with which the plasmonic enhancement effects occur, we herein review the recent progress in the field of plasmonic water splitting by classifying different obstacles and breakthroughs made over the past decade and a half. While plasmonic nanostructures initially served to expand the light harvesting spectrum of semiconductors, rational designs and advanced fabrication techniques have increasingly improved the light absorption capabilities of the plasmonic metal/semiconductor hybrid architectures as a whole. More recently, the use of various analytical tools has allowed a more fundamental issue of short hot carrier lifetime to be tackled which, in turn, has brought about great interest in optimizing the structures and interfaces for more efficient charge transfer. Other issues associated with the field include the complexity of fabrication methods, limited choices in material selection, and cost effectiveness. The review ends with perspectives on future steps to be taken namely the incorporation of co catalysts, the possibility of using plasmonic heating to assist the catalytic activities, and further investigation of the direct interfacial charge transfer mechanism driven by chemical interface damping (CID)
author_names: Joong Bum Lee

Shinyoung Choi

Jeonga Kim

Yoon Sung Nam
title: Plasmonically assisted nanoarchitectures for solar water splitting: Obstacles and breakthroughs
year: 2017

abstract: An ultrasonication assisted in situ deposition strategy was utilised to uniformly decorate plasmonic Ag nanoparticles on vertically aligned TiO2 nanotube arrays (NTAs) to construct a Ag@TiO2 NTA composite. The Ag nanoparticles act as efficient surface plasmon resonance (SPR) photosensitizers to drive photocatalytic water splitting under visible light irradiation. The Ag nanoparticles were uniformly deposited on the surface and inside the highly oriented TiO2 nanotubes. The visible light driven hydrogen production activities of silver nanoparticle anchored TiO2 nanotube array photocatalysts were evaluated using methanol as a sacrificial reagent in water under a 500 W Xe lamp with a UV light cutoff filter (l 420 nm) It was found that the hydrogen production rate of the Ag@TiO2 NTAs prepared with ultrasonication assisted deposition for 5 min was approximately 15 times higher than that of its pristine TiO2 NTAs counterpart. The highly efficient photocatalytic hydrogen evolution is attributed to the SPR effect of Ag for enhanced visible light absorption and boosting the photogenerated electron hole separation/transfer. This strategy is promising for the design and construction of high efficiency TiO2 based photocatalysts for solar energy conversion.
author_names: Mingzheng Ge

Chunyan Cao

Shu-hui Li

Yu Xin Tang

Lu-ning Wang

Ning Qi

Jianying Huang

Ke-Qin Zhang

Salem Slayyem Al-Deyab

Yuekun Lai
title: In situ plasmonic Ag nanoparticle anchored TiO2 nanotube arrays as visible light driven photocatalysts for enhanced water splitting.
venue: Nanoscale
year: 2016

abstract: Recent years have seen a renewed interest in the harvesting and conversion of solar energy. Among various technologies, the direct conversion of solar to chemical energy using photocatalysts has received significant attention. Although heterogeneous photocatalysts are almost exclusively semiconductors, it has been demonstrated recently that plasmonic nanostructures of noble metals (mainly silver and gold) also show significant promise. Here we review recent progress in using plasmonic metallic nanostructures in the field of photocatalysis. We focus on plasmon enhanced water splitting on composite photocatalysts containing semiconductor and plasmonic metal building blocks, and recently reported plasmon mediated photocatalytic reactions on plasmonic nanostructures of noble metals. We also discuss the areas where major advancements are needed to move the field of plasmon mediated photocatalysis forward.
author_names: Suljo Linic

Phillip Christopher

David B Ingram
title: Plasmonic metal nanostructures for efficient conversion of solar to chemical energy.
venue: Nature materials
year: 2011

abstract: To design an efficient photocatalyst (PC) for semiconductor (SC) mediated, solar driven water dissociation to generate hydrogen, a host of strategies has been adopted, including the fabrication of semiconductor composites, substitution of impurities for achieving extended absorbance, and coating with a metal to promote charge transfer. Despite these efforts, a photocatalyst exhibiting requisite efficiency has not been developed. This article reviews the factors governing the water splitting photoactivity of an SC material, and provides an account of our recent research on this subject. As per our investigations, the mode of adsorption of the water molecules on the semiconductor surface and their subsequent interaction with the charge carriers play a crucial role in the overall performance of a water splitting photocatalyst, rather than the much discussed SC SC or SC metal charge transfer effects alone. The water to SC binding is controlled by a combination of several physicochemical properties of a composite PC, such as the preparation dependent grain morphology, doping affected grain nucleation, pore structure dependent water adsorption/desorption kinetics, exposure of specific facets, and SC/SC or SC/metal interfacial characteristics. Our studies revealed strong particle size dependence and the facet based sensitivity of modified metal sulfide and metal oxide photocatalysts. Additionally, the effect of lattice impurity on quantum efficiency of wide gap metal oxides, such as TiO2, In2TiO5, InVO4, FeNbO4, GaNbO4, GaFeO3, and LaInO3, is related to the lattice defect induced intra bandgap energy levels rather than the doping induced extension of visible region absorbance. Furthermore, the dispersed gold nanoparticles served as distinct reaction sites over the surface of a TiO2 photocatalyst besides their contribution to the plasmonic effect. Our study revealed that under certain spectral overlap conditions, the inter semiconductor charge transfer might cause quenching of the water splitting photoactivity of a composite photocatalyst. We surmise that considering the aforementioned factors should assist in designing an efficient water splitting PC, eventually triggering technological advancements in this field.
author_names: Narendra M Gupta
title: Factors affecting the efficiency of a water splitting photocatalyst: A perspective
year: 2017

abstract: Plasmonic photoelectrochemical (PEC) water splitting is very promising in the conversion of abundant solar energy into chemical energy. However, the solar to hydrogen efficiencies reported so far are still too low for practical use, which can be improved by optimizing the design and synthesis of individual blocks (i. e. the compositions, sizes, shapes of the metal and the coupling semiconductors) and the assembly of these blocks into targeted three dimensional (3D) structures. Here, we constructed a composite plasmonic metal/semiconductor photoanode by decorating gold nanoparticles (Au NPs) on 3D branched ZnO nanowire arrays (B ZnO NWs) through a series of simple solution chemical routes. The 3D ordered Au/B ZnO NWs photoanodes exhibited excellent PEC activities in both ultraviolet and visible region. The improved photoactivities in visible region were demonstrated to be caused by the surface plasmon resonance effect of Au NPs. The photoconversion efficiency of Au/B ZnO NWs photoanode reached 0.52% under simulated sunlight illumination. This is a high value of solar to hydrogen efficiencies reported till nowadays for plasmonic PEC water splitting, which was mainly benefit from the extensive metal/semiconductor interfaces for efficient extraction of hot electron from Au NPs and excellent charge carries collection efficiency of the 3D ordered Au/B ZnO NWs photoelectrode.
author_names: Xing Zhang

Yang Liu

Zhenhui Kang
title: 3D branched ZnO nanowire arrays decorated with plasmonic au nanoparticles for high performance photoelectrochemical water splitting.
venue: ACS applied materials interfaces
year: 2014