In this work, we revisit the polaron-mediated charge transport in BiVO4 photoanode. In addition to the improved charge transport and increased donor density, experimental and calculated results unravel that the electron small polaron hopping barrier near OVs of the BiVO4 is decreased by mild hydrogen doping, and the liberated polaron hopping is likely due to the filling of OVs with substitutional hydrogen dopants. This work illustrates an alternative understanding of the reasons for the commonly observed superior photoelectrochemical performances demonstrated in hydrogen-treated semiconductors.
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ACS Energy Lett. 2023, Volume 8, Issue 5, 12 May 23, 2023, Pages 2177-2184.
In this work, we report the active site modulation over oxygen-deficient TiO2 by copper loading, which enhances the electrocatalytic nitrogen reduction reaction to ammonia. Both oxygen vacancies and copper nanoparticles serve as the active sites. The strong metal–support interaction between them also leads to the better activation of N2 molecules.
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SMALL 2022, Volume 18, Issue 25, June 23, 2022, Pages 2200996.
Taking 3DOM and bulk BiVO4 as studied materials for comparison, this work systematically reveals the different carrier dynamics, including surface work function, charge mobilities, and charge carrier lifetimes, as well as effective diffusion lengths between them. The 3DOM BiVO4 with high crystallinity connected by an ultrathin internal wall shows the quantum confinement effect. This study presents an alternative view in understanding the underlying reasons for the commonly observed superior photocatalytic performances demonstrated in highly ordered porous photocatalysts.
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ACS Energy Lett. 2021, Volume 6, Issue 10, Oct. 8, 2021, Pages 3400-3407.
The cover image, highlighting the work by our team,and co-workers in SMALL, shows the photoelectrochemical water oxidation on an illuminated plate-like bismuth tungstate photoanode thin film. The tungsten concentration is modulated to tune the photoexcited charge transportation of the thin film. This “self-doped” of tungsten leads to the higher carrier density and improved conductivity for oxygen evolution from water.
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SMALL 2021, Volume 17, Issue 35, Sept. 2, 2021, Pages 2102023
In this article, we show that electrochemical exfoliation and oxygen nucleation of MoS2 nanosheet thin film supercapacitor electrodes results in enhanced capacitance. The nucleation and growth of the MoS2−xOx phase also shifts the charge storage process of the MoS2 nanosheet thin film supercapacitors from a diffusion-limited process to a capacitive-dominant process.
ChemSusChem 2021, Volume 14, Issue 14 July 22, 2021, Pages 2882-2891
This book focuses on emerging techniques in heterogeneous catalysis, from new methodology for catalysts design and synthesis, surface studies and operando spectroscopies, ab initio techniques, to critical catalytic systems as relevant to energy and the environment. It provides the vision of addressing the foreseeable knowledge gap unfilled by classical knowledge in the field.
Heterogeneous Catalysts: Advanced Design, Characterization and Applications begins with an overview on the evolution in catalysts synthesis and introduces readers to facets engineering on catalysts; electrochemical synthesis of nanostructured catalytic thin films; and bandgap engineering of semiconductor photocatalysts. Next, it examines how we are gaining a more precise understanding of catalytic events and materials under working conditions. It covers bridging pressure gap in surface catalytic studies; tomography in catalysts design; and resolving catalyst performance at nanoscale via fluorescence microscopy. Quantum approaches to predicting molecular reactions on catalytic surfaces follows that, along with chapters on Density Functional Theory in heterogeneous catalysis; first principles simulation of electrified interfaces in electrochemistry; and high-throughput computational design of novel catalytic materials.
Heterogeneous Catalysts: Advanced Design, Characterization, and Applications, 2 Volumes
ISBN: 978-3-527-34415-4 March 2021 768 Pages
In this article, we show that oxygen functionalities on GIO/GO are involved in the formation of active Al sites potentially with a microwave-absorbing ability, which facilitates glucose–fructose isomerisation in water.
Green Chem. 2019, Volume 21, Issue 16 May 17, 2019, Pages 4341-4353
In this article, we report that the composition-tunable mixed Brønsted/Lewis acids on silica-alumina and silica-alumina-phosphate prepared by the rapid flame spray pyrolysis can produce exceptionally high glucose-to-levulinic acid yield, twice that of commercial ZSM-5 and Zeolite X.
Green Chem. 2019, Volume 22, Issue 3 Nov 14, 2019, Pages 688-698
To address the environmental and energy problems caused by the rapid consumption of fossil fuels, water splitting for hydrogen production by utilizing semiconductor photocatalysts has been extensively studied as a promising route to produce clean and renewable hydrogen. In article 1800184, we review some main strategies to construct various dimensional TiO2 nanostructures, and modified strategies to enhance solar light harvesting and energy conversion efficiency. Furthermore, the mechanism and potential applications of sustainable photo/photoelectro-catalytic hydrogen production are comprehensively summarized and discussed.
Small Methods 2019, Volume 3, Issue 1 January 16, 2019, Pages 1800184
The front cover shows ultrathin Co3O4 nanoflakes that are deposited on ZnO nanorods by pulsed electrodeposition. The performance of the nanostructured hybrid Co3O4/ZnO anode in electrochemical O2 evolution is better than that of neat Co3O4. Well‐aligned onedimensional ZnO nanorod arrays are integrated as a scaffold which functions as a “highway” to facilitate improved charge transfer, while the porosity of the anode material allows the penetration of the electrolyte, thus promoting efficient utilization of the catalytically active species. Details are given in the Full Paper by Y. Tang, Y. H. Ng, and co‐workers (DOI:10.1002/cplu.201800218).
ChemPlusChem 2018, Volume 83, Issue 10, October 2018, Pages 934-940
In this article, we report the establishment of a solar-chargeable intercalation battery and an operando synchrotron X-ray diffraction technique that enables realtime tracking of the dynamic structural change of a solar battery electrode from a photo-intercalation reaction. By analyzing the structural prerequisite for light-induced intercalation reaction, novel materials with tailored electrode structures and conductivities can be designed to enhance solar battery technology.
Adv. Energy Mater. 2017, Volume 7, Issue 19, October, 2017, article 1700545.
In this work, we demonstrated the successful construction of metal-free zero dimensional/ two-dimensional carbon nanodot-hybridized protonated g-C3N4 heterojunction photocatalysts by means of electrostatic attraction. The efficient shuttling of electrons from the conduction band of protonated g-C3N4 to carbon nanodot hampers the recombination of electron–hole pairs. This significantly increased the probability of free charge carriers reducing CO2 to CH4 and CO. Overall, this study underlines the importance of understanding the charge carrier dynamics of the CND/pCN hybrid nanocomposites, in order to enhance solar energy conversion.
Nano Res. 2017, Volume 10, Issue 5, May , 2017, Pages 1673-1696.
On page 9949, we describe Au-Pt-Ni core-sandwich-shell nanorods for high selectivity H2O2 production via direct oxygen reduction. The epitaxial growth allowed for the tuning of the oxygen reduction pathway to selective 2e- reduction. Moreover, the transitional high-work-function Pt at the interface is believed to further influence the degree of lattice strain, and hence further positively affecting the catalytic properties.
Adv. Mater. 2016, Volume 28, Issue 45, December 7, 2016, Pages 9949-9955.
Excellent photoelectrochemical performance of bismuth vanadate in water splitting is achieved by coupling with graphene sheets. On page 5295, R. Amal, S. C. Smith, Y. H. Ng, and co-workers, demonstrate the ability to achieve efficient interfacial charge transfer between bismuth vanadate and graphene sheets by modulating the exposure extent of {010}/{110} facets of bismuth vanadate. The overall photoactivity is governed by the quality of bismuth vanadate-graphene interfaces. These findings would be useful in guiding the development of efficient photoelectrochemical sensors, photo-induced hydrogen generation, and solar cells.
SMALL 2016, Volume 12, Issue 38, October 12, 2016, Pages 5295–5302
A cost-effective electrocatalyst composed of graphitic carbon nitride and multiwall carbon nanotubes was fabricated for the electrochemical reduction of CO2. C–N bonds were formed between these two components providing active sites for the CO2reduction reaction. The catalyst can reduce CO2 exclusively to CO with a high selectivity and stability in aqueous media.
Chem. Eur. J. 2016, Volume 22, Issue 34, August 16, 2016, Pages 11991–11996
Vertically aligned ZnO nanorod arrays on a fluorine doped tin oxide (FTO) substrate were uniformly coated with visible light active CuInS2 nanoparticles using electrodeposition regulated by using an optimized frequency. As the diffusion of the fresh metallic precursor to the bottom of the one-dimensional nanostructure is the major challenge during electrodeposition, frequency tuning has demonstrated its effectiveness in balancing the diffusion and deposition of the secondary component (CuInS2) on the one-dimensional substrate (ZnO). The high quality of the heterojunction between CuInS2 and ZnO together with their intimate interaction facilitated efficient charge shuttling from CuInS2 to ZnO to yield a four-fold visible light response compared with traditionally synthesized CuInS2–ZnO nanostructures.
J. Mater. Chem. A 2015, 3 (31), 15876-15881