Proceedings of nanoGe Fall Meeting 2018 (NFM18)
Publication date: 6th July 2018
Cocatalysts are critical in photochemical water splitting reactions, as they increase the photocatalytic activity and inhibit corrosion of photocatalysts. To achieve a high photocatalytic activity, the loading amount of the cocatalysts is to be optimized, together with their size, separation and nanostructure [1].
We selected TBACa2Nb3O10 nanosheets as the photoabsorber for ultraviolet light, as they provide large surface areas to incorporate cocatalysts. Pt and IrO2 have been demonstrated as good cocatalysts for the half reactions of hydrogen evolution and oxygen evolution, respectively [2]. We study the activity of earth-abundant NiOx cocatalysts on these nanosheets and the correlation to their nanostructures.
NiOx was impregnated into photocatalytically active TBACa2Nb3O10 nanosheets. Then, depending on the calcination processes, various nanostructures were synthesized, including Ni(OH)2 layers, NiO nanoparticles, and Ni nanoparticles with a NiO shell. The optimized loading amount was determined by the hydrogen evolution rates from methanol reforming. All nanostructures show activity of methanol reforming, whereas the core/shell nanoparticles have the highest activity.
Besides using atomic resolution electron microscopy and electron spectroscopy to characterize the various NiOx nanostructures, we study the evolution of the nanostructures upon calcination using a heating holder inside the electron microscope. NiOx nanoparticles were nucleated as the Ni(OH)2 layer decomposes. We observed heterogeneous nucleation of nanoparticles at lower calcination temperatures and homogeneous nucleation at higher temperatures. Abnormal growth of nanoparticles were also observed at higher temperatures, as the diffusion pathways between the nanoparticles were activated for Ostwald ripening.
The in situ study on the structural evolution reveals challenges to get homogeneously small sizes of NiOx nanoparticles, the desirable morphology for high photocatalytic activity. We propose the introduction of nucleation sites to promote nanoparticle nucleation at lower calcination temperatures.
[1] Ran J., et al., Chem. Soc. Rev. 43, 7787 (2014).
[2] Sabio E.M., et al., Langmuir 26, 7254 (2010).
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.