Green Hydrogen Production in an Optofluidic Planar Microreactor via Photocatalytic Water Splitting under Visible/Simulated Sunlight Irradiation

Abstract

The visible light-active Pt/TiO2 photocatalyst thin films were prepared by photo-depositing Pt onto the sol–gel TiO2 spin-coated films. An optofluidic planar microreactor was fabricated using a Pt/TiO2 film-coated glass substrate as the bottom plate and an uncoated glass substrate containing a planar reaction chamber as the cover plate. The Pt/TiO2 thin films were tested for the photocatalytic water splitting activity in the presence of methanol as the sacrificial agent to produce hydrogen under visible/solar light irradiation. The effect of catalyst film thickness, reactant flow rate, light intensity, and type of light source on the rate of hydrogen production was studied. The Pt/TiO2 film with a thickness of 1650 ± 119 nm showed a highest rate of 16.35 mmol h–1 g–1 (4.7 μmol h–1 cm–2) hydrogen production at an optimum reactant flow rate of 0.3 mL min–1 under visible light (400 W metal halide lamp) irradiation. The stability study carried out for four cycles of 5 h runs proved that the photocatalyst was stable and the film was well adhered to the glass substrate. A hydrogen production rate of 0.766 mmol h–1 g–1 (0.22 μmol h–1 cm–2) and a solar to hydrogen conversion efficiency of 0.015% were obtained under a simulated solar light irradiation of ∼100 mW cm–2 intensity, proving the solar light activity of the Pt/TiO2 film.

Glycerol selective oxidation to lactic acid over platinum–vanadium bimetallic catalysts supported on activated carbon

“…Those at 71.3 and 75.2 eV are related to 4f 7/2 and 4f 5/2 of the Pt oxide phase (PtO). 43 For the Pt–V/AC catalyst (Fig. 2b), similar XPS signals of metallic Pt (72.1 eV for Pt 4f 7/2 , 75.0 eV for Pt 4f 5/2 ) and Pt( ii ) species (71.4 eV for Pt 4f 7/2 , 75.3 eV for Pt 4f 5/2 ) were also observed.…”

“…2b), two distinct Pt species are present, as evidenced by the broadening and small valley between the spin–orbit components on the catalyst surface. 43,44 The deconvolution reveals that the 71.9 and 74.8 eV binding energy peaks correspond to 4f 7/2 and 4f 5/2 of the Pt metallic phase. Those at 71.3 and 75.2 eV are related to 4f 7/2 and 4f 5/2 of the Pt oxide phase (PtO).…”

Continuous Flow Photocatalytic Hydrogen Production from Water Synergistically Activated by TiO2, Gold Nanoparticles, and Carbon Nanotubes

“…Yet, no integration of TiO 2 /CNT in microfluidic devices has been reported so far. TiO 2 -based microreactors for photocatalytic water splitting rely, for example, on planar microreactors incorporating Pt/TiO 2 photocatalyst thin films [ 45 , 46 ] that lead to a hydrogen production rate of 766 µmol g −1 h −1 under a simulated solar light irradiation. In other examples, the loading of Pt/TiO 2 photocatalyst was achieved by a casting-transfer method on the PDMS matrix constituting the walls of the microreactor, or by the coating of the micro-pillars [ 47 ] in the reaction micro-chamber.…”

A Minireview on the Role of Cocatalysts in Semiconductor-Based Photocatalytic CH4 Conversion

“…The global energy crisis and environmental pollution problems have been more and more conspicuous since the last century. 1 Searching alternative carbon source is demanding to replace fossils. Methane (CH 4 ) is considered as one of the substitutes to nonrenewable crude oil due to its rich resource reserves.…”

“…The global energy crisis and environmental pollution problems have been more and more conspicuous since the last century . Searching alternative carbon source is demanding to replace fossils.…”