Hydrogen Production from Water by Photolysis, Sonolysis and Sonophotolysis with Solid Solutions of Rare Earth, Gallium and Indium Oxides as Heterogeneous Catalysts

Abstract

Abstract:In this work, we present the hydrogen production by photolysis, sonolysis and sonophotolysis of water in the presence of newly synthesized solid solutions of rare earth, gallium and indium oxides playing as catalysts. From the experiments of photolysis, we found that the best photocatalyst is the solid solution Y0.8Ga0.2InO3 doped by sulphur atoms. In experiments of sonolysis, we optimized the rate of hydrogen production by changing the amount of water, adding ethanol and tuning the power of our piezoelectric transducer. Finally, we performed sonolysis and sonophotolysis experiments in the presence of S:Y0.8Ga0.2InO3 finding a promising synergistic effect of UV-visible electromagnetic waves and 38 kHz ultrasound waves in producing H2. OPEN ACCESSSustainability 2015, 7 9311

A Combined Approach using Sonochemistry and Photocatalysis: How to Apply Sonophotocatalysis for Biomass Conversion?

“…We can draw inspiration from the sonophotocatalytic production of H 2 from water/ethanol in the presence of a heterogeneous catalyst (Y 0.8 Ga 0.2 InO 3 doped by sulfur atoms) . Under hybrid action of US (38 kHz, 50 W) and light (500 W Xenon lamp), the production of H 2 was improved compared to sonocatalysis or photocatalysis, applied separately.…”

“…We can draw inspiration from the sonophotocatalytic productiono fH 2 from water/ethanol in thep resence of ah eterogeneousc atalyst( Y 0.8 Ga 0.2 InO 3 doped by sulfur atoms). [73] Under hybrid action of US (38 kHz, 50 W) and light (500 W Xenon lamp),t he production of H 2 wasi mproved compared to sonocatalysis or photocatalysis, applied separately.This synergy dependso nt he mass of liquid (watera nd ethanol) introduced into the reactor, which is more important in diluteds uspensions rather than in concentrated ones. [74] Several complementary parameters and/or conditions should be investigated more in depth, such as the sourceo ff requency,w ave shape, surface/volume ratio of liquid,u se of catalysis, reactor engineering especially in flow,e tc, so as to better depict the efficiency of this sonophotocatalytic processI nt he same way, the production of biomethane from sugarcane bagasse, using nano-TiO 2 pretreatment suggests that sonophotocatalysis can be used as an efficient pretreatment method for the anaerobic digestion of biomass and the enhancement of the formation of biofuel products.…”

Sonochemical fabrication of inorganic nanoparticles for applications in catalysis

“…Compared to the pure metal counterparts, heterogeneous metal catalysts doped with inorganic compounds or complexes are active under certain conditions, and has an enhanced activity and selectivity and an increased tolerance to some simple substances and compounds. [72] , [73] , [74] The sonochemically treating platinum catalysts (e.g., Pt/C, Pt/Al 2 O 3 , Pt/SiO 2 and Pt/montmorillonite) could lead to an substantially increased enantioselectivity in many processes. In the case of ethyl pyruvate hydrogenated to ethyl lactate, the hydrogenation rate with treated catalyst was increased by an order of magnitude compared with the untreated one, and the yield of targeting product reached up to 100%.…”

Sonocatalysis: A Potential Sustainable Pathway for the Valorization of Lignocellulosic Biomass and Derivatives

“…More significant scientific breakthroughs for biomass valorization are expected to occur in this innovative field in the near future. Last, but not least, and continuing in the same lines, the important role of ultrasound on photocatalysis (ultrasound and photocatalysis together) for the valorization of lignocellulosic biomass and its derivatives might be also a promising research avenue worth broad interest in the huge spectrum of possibilities offered by lignocellulose-based processes, for instance, sonophotocatalytic proof concepts for: lignocellulosic biomass depolymerization [ 81 ], biohydrogen [ 82 ], and biomethane production [ 83 ].…”