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Summary: Previous works indicated that aluminum hydroxide could be acted as catalyst to speed up the hydrolysis reaction of Al, and the catalytic activity of aluminum hydroxide is related to its microscopic properties. In this work, the effect of crystalline phases of aluminum hydroxide catalysts on Al hydrolysis is researched systematically. The results show that the hydrogen production performance of Al hydrolysis catalyzed by aluminum hydroxide with different crystalline phases is obviously different, and the catalytic activity of different aluminum hydroxides is in the order of boehmite > bayerite > gibbsite. A possible mechanism is given, which reveals that the surface hydroxyl groups of aluminum hydroxide act as anchoring sites for the adsorption of H2O molecules and decrease the dissociative adsorption energy of H2O molecules on aluminum hydroxides surface, promoting the hydrolysis reaction of Al. Consequently, the difference in catalytic activity of aluminum hydroxide with different crystalline phases is attributed to the difference in surface hydroxyl group density. This study provides a new idea for the synthesization of aluminum hydroxide with excellent catalytic activity. [ABSTRACT FROM AUTHOR]

Highlights: [•] AgCu) x ln2xZn2(1−2x)S2 were successfully prepared by ultrasonic-hydrothermal method. [•] The band-structure of (AgCu) x ln2xZn2(1−2x)S2 can be controlled by changing x value. [•] A formation mechanism of microsphere was proposed based on characterization results. [•] The solid solutions were active photocatalysts for H2 production. [ABSTRACT FROM AUTHOR]

Abstract: Using various organics as electron donor, (CuIn)0.2Zn1.6S2 microsphere solid solution prepared via hydrothermal method as photocatalyst, hydrogen production by anaerobic photocatalytic reforming organics were researched. The photocatalytic hydrogen production activity was notably enhanced in the presence of the organic electron donors. Formic acid was found to be the most efficient sacrificial agent among methanol, glucose, triethanolamine and formic acid. The effects of initial formic acid concentration on hydrogen generation were investigated. When the initial formic acid concentration was 10 vol%, the photocatalytic activity reached the highest. The average activity in initial 10 h can amount to 144 μmol h−1. The possible mechanism of photocatalytic reaction for hydrogen production with simultaneous formic acid degradation was discussed preliminary. [Copyright &y& Elsevier]

Abstract: A series of Ni2+ doped Cd0.1Zn0.9S photocatalysts were prepared with different salt by hydrothermal method. The prepared photocatalysts were characterized by XRD, UV–Vis, BET and SEM. The effects of SO4 2−, CH3COO−, Cl− and NO3 − anions on the photocatalytic hydrogen production performance of these photocatalysts were examined. Experimental results showed that the photocatalysts prepared with acetates and chlorides have the highest hydrogen production activity, and their initial hydrogen production rate reaches to 76.52 μmol/h and 80.75 μmol/h under visible-light irradiation with the apparent quantum yield of 12.30% and 14.36% at 420 nm without any noble metal loading, respectively. The absence of noble metal is propitious to reduce the cost of photocatalyst preparation. [Copyright &y& Elsevier]

Abstract: (CuIn) x Zn2(1-x)S2 (x = 0.01–0.5) microspheres were prepared by a simple hydrothermal method. They were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Visible diffuse reflectance spectra (UV–Vis), Raman scattering spectra and Brunauer-Emmett-Teller (BET) surface area measurement. It was found that the (CuIn) x Zn2(1-x)S2 samples formed solid solution only in the presence of surfactant cetyltrimethylammonium bromide (CTAB). CTAB enabled the increase of the surface area for the (CuIn) x Zn2(1-x)S2 solid solutions. Diffuse reflection spectra of the solid solutions shifted monotonically to long wavelength side as the value of x increased. The photocatalytic H2 evolution activity under visible-light irradiation of the solid solutions was evaluated. The result showed that the activity depended on their corresponding compositions closely. Ru (1.5 wt%)-loaded (CuIn)0.2Zn1.6S2 showed the highest photocatalytic activity of 198.09 μmol h−1 under visible-light irradiation, and the apparent quantum yield amounted to 15.45% at 420 nm. Furthermore, the density functional theory (DFT) calculations showed that the solid solution with the ration of ZnS and CuInS2, 6:1, was a direct band gap semiconductor. The valence band consisted of the hybrid orbital of S 3p and Cu 3d and the conduction band consisted of In 5s5p orbital mixed with Zn 4s4p. The energy band structure resulted in the visible-light response of the solid solution, and affected its photocatalytic performance. [Copyright &y& Elsevier]

Abstract: Ni2+ doped Cd1−x Zn x S microsphere photocatalysts were prepared by a new hydrothermal method. Experimental results showed that the doped Ni2+ can not only affect the crystal structure and morphology of Cd1−x Zn x S photocatalysts, but also greatly improve its photocatalytic activity. It was found that 0.1wt% Ni2+ doped Cd0.1Zn0.9S photocatalyst showed the highest activity with the apparent quantum yield of 15.9% at 420nm. The reason for the positive effects of Ni2+ was discussed. [Copyright &y& Elsevier]

Abstract: In despite of so many types of solar reactors designed for solar detoxification purposes, few attempts have been made for photocatalytic hydrogen production, which in our option, is one of the most promising approaches for solar to chemical energy conversion. Addressing both the similarity and dissimilarity for these two processes and by fully considering the special requirements for the latter reaction, a Compound Parabolic Concentrator (CPC) based photocatalytic hydrogen production solar reactor has been designed for the first time. The design and optimization of this CPC based solar reactor has been discussed in detail. Preliminary results demonstrated that efficient photocatalytic hydrogen production under direct solar light can be accomplished by coupling tubular reactors with CPC concentrators. It is anticipated that this first demonstration of concentrator-based solar photocatalytic hydrogen production would draw attention for further studies in this promising direction. [Copyright &y& Elsevier]

[Display omitted] • Both US and AH greatly enhanced hydrogen production performance of Al hydrolysis. • US and AH increased v max from 6.8 to 33.0 and 28.0 ml·min−1·g−1-Al, respectively. • For AH + US, induction time was 0.17 h and v max was as high as 66.0 ml·min−1·g−1-Al. • AH + US exhibited the best performance due to synergistic effect between AH and US. Ultrasound can accelerate and change the reaction process and is widely used in the field of hydrogen production and storage. In this study, ultrasound (US) and AlOOH suspension (AH) are used to promote hydrogen production from Al hydrolysis. The results indicate that both US and AH greatly shorten the induction time and enhance the hydrogen production rate and yield. The promoting effect of US and AH on Al hydrolysis originates from the acoustic cavitation effect and catalytic effect, respectively. When AH is used in combination with US, Al hydrolysis has the best hydrogen production performance and the hydrogen yield can reach 96.6 % within 1.2 h, because there is a synergistic effect on Al hydrolysis between AH and US. Mechanism analyses reveal that the micro-jets and local high temperature environment arising from acoustic cavitation improve the catalytic activity of AlOOH, while the suspended AlOOH particles enhance the cavitation effect of US. This work provides a novel and feasible method to promote hydrogen production from Al hydrolysis. [ABSTRACT FROM AUTHOR]

In this work, we introduce a Rhodium-Ceria-Zirconia (Rh/CZ) internal reforming catalyst layer to a high-performance metal-supported solid oxide fuel cell (MS-SOFC). The catalyst is applied by infiltrating Rh, CeO 2 , and ZrO 2 precursors into the stainless steel (SS 430) support. The cell is tested by directly feeding an ethanol solution (45 vol%) into the anode at 600 °C. Our experimental results show that the button cell with the infiltrated 5 wt% Rh/CZ demonstrates an improved performance over the button cell without the catalyst layer by enhancing the internal reforming activity of ethanol toward the production of synthesis gas. The maximum current density improved from 0.3 A cm−2 to 0.4 A cm−2 while the long-term stability was also greatly improved. Post mortem cell analysis reveals that the infiltrated catalyst layer can prevent severe coke deposition from the cell's anode functional layer. The proposed integrated reforming catalyst and MS-SOFC system is a promising pathway to enable bioethanol fed-SOFC technology for future electric vehicles. [Display omitted] • Catalyst infiltration into metal-supported solid oxide fuel cell (MS-SOFC). • MS-SOFC with the catalyst successfully operates under direct-ethanol feed condition. • MS-SOFC with the catalyst shows enhanced synthesis gas production rate. • MS-SOFC with the catalyst offers increased mass transfer limited current density. • MS-SOFC with the catalyst offers enhanced stability with increased coking resistance. [ABSTRACT FROM AUTHOR]

Abstract: Photocatalytic water splitting with solar light is one of the most promising technologies for solar hydrogen production. From a systematic point of view, whether it is photocatalyst and reaction system development or the reactor-related design, the essentials could be summarized as: photon transfer limitations and mass transfer limitations (in the case of liquid phase reactions). Optimization of these two issues are therefore given special attention throughout our study. In this review, the state of the art for the research of photocatalytic hydrogen production, both outcomes and challenges in this field, were briefly reviewed. Research progress of our lab, from fundamental study of photocatalyst preparation to reactor configuration and pilot level demonstration, were introduced, showing the complete process of our effort for this technology to be economic viable in the near future. Our systematic and continuous study in this field lead to the development of a Compound Parabolic Concentrator (CPC) based photocatalytic hydrogen production solar rector for the first time. We have demonstrated the feasibility for efficient photocatalytic hydrogen production under direct solar light. The exiting challenges and difficulties for this technology to proceed from successful laboratory photocatalysis set-up up to an industrially relevant scale are also proposed. These issues have been the object of our research and would also be the direction of our study in future. [Copyright &y& Elsevier]