Demonstration of the photothermal catalysis of the Sabatier reaction using nickel nanoparticles and solar spectrum light.

The promise of light-to-chemical energy conversion has led researchers to explore photo-thermal processes for chemical reactivity of nanoparticles. Previous work has examined particles as an element of a supported catalyst, but not as an unsupported nanopowder. We present a preliminary examination of a photo-thermal Sabatier reaction performed on suspended Ni nanoparticles. This new system performs a catalytic Sabatier reaction at lower bulk temperatures than reported for a standard reaction, driven by light. This result occurs only when the particles are suspended freely in a gaseous mixture; implying that particle isolation enhances photo-thermal catalysis.

Photothermal Nanoparticle Initiation Enables Radical Polymerization and Yields Unique, Uniform Microfibers with Broad Spectrum Light.

Photothermal processes are utilized across a variety of fields, from separations to medicine, and are an area of active research. Herein, the action of a solar simulator upon carbon black nanoparticles is shown to result in photothermally initiated chain-growth polymerization of methyl acrylate, butyl acrylate, and methyl methacrylate initiated by benzoyl peroxide. With use of methyl acrylate as the model system, products from this reaction are shown to be apparently indistinguishable on the molecular level, but result in unique microstructures relative to the thermal controls. The relative contribution of bands of the UV/visible spectrum to the polymerization initiation show that red/infrared wavelengths are most important for the initiation to occur. Kinetic analysis of the initiator homolysis indicate that the apparent reaction rate is accelerated in the photothermal condition.