Improved Photoelectrochemical Hydrogen Gas Generation on Sb2S3 Films Modified with an Earth-Abundant MoSx Co-Catalyst

Moisés A. de Araújo ◽  
Magno B. Costa ◽  
Lucia H. Mascaro
2018 ◽  
Vol 9 ◽  
pp. 2432-2442 ◽  
Malkeshkumar Patel ◽  
Joondong Kim

Co3O4 has been widely studied as a catalyst when coupled with a photoactive material during hydrogen production using water splitting. Here, we demonstrate a photoactive spinel Co3O4 electrode grown by the Kirkendall diffusion thermal oxidation of Co nanoparticles. The thickness-dependent structural, physical, optical, and electrical properties of Co3O4 samples are comprehensively studied. Our analysis shows that two bandgaps of 1.5 eV and 2.1 eV coexist with p-type conductivity in porous and semitransparent Co3O4 samples, which exhibit light-induced photocurrent in photoelectrochemical cells (PEC) containing the alkaline electrolyte. The thickness-dependent properties of Co3O4 related to its use as a working electrode in PEC cells are extensively studied and show potential for the application in water oxidation and reduction processes. To demonstrate the stability, an alkaline cell was composed for the water splitting system by using two Co3O4 photoelectrodes. The oxygen gas generation rate was obtained to be 7.17 mL·h−1 cm−1. Meanwhile, hydrogen gas generation rate was almost twice of 14.35 mL·h−1·cm−1 indicating the stoichiometric ratio of 1:2. We propose that a semitransparent Co3O4 photoactive electrode is a prospective candidate for use in PEC cells via heterojunctions for hydrogen generation.

2020 ◽  
Fatma Pelin Kinik ◽  
Tu Ngugen ◽  
Mounir Mensi ◽  
Christopher Ireland ◽  
Kyriakos Stylianou ◽  

<div> <div> <div> <p>Metal nanoparticles (NPs) are usually stabilized by a capping agent, a surfactant, or a support material, to maintain their integrity. However, these strategies can impact their intrinsic catalytic activity. Here, we demonstrate that the in-situ formation of copper NPs (Cu0NPs) upon the reduction of the earth-abundant Jacquesdietrichite mineral with ammonia borane (NH3BH3, AB) can provide an alternative solution for stability issues. During the formation of Cu0NPs, hydrogen gas is released from AB, and utilized for the reduction of nitroarenes to their corresponding anilines, at room temperature and under ambient pressure. After the nitroarene-to-aniline conversion is completed, regeneration of the mineral occurs upon the exposure of Cu0NPs to air. Thus, the hydrogenation reaction can be performed multiple times without the loss of the Cu0NPs’ activity. As a proof-of-concept, the hydrogenation of drug molecules “flutamide” and “nimesulide” was also performed and isolated their corresponding amino-compounds in high selectivity and yield. </p> </div> </div> </div>

1978 ◽  
Vol 100 (3) ◽  
pp. 313-318 ◽  
G. F. Pittinato

Water heat pipes were fabricated from 316, 347, and 430 stainless steel, Monel 400, CDA 715, Inconel 600, and Incoloy 800. All of these materials generated varying amounts of hydrogen gas during the first few days of operation. However, as the heat pipes continued to operate, the amount of gas in each heat pipe, excluding 430 stainless steel, decreased by permeating through the heat pipe walls. Inconel 600 appeared to be the most acceptable material for water heat pipes by returning to isothermal operation over a short time period. An equation based on a diffusion dependent mechanism was developed that predicts heat pipe performance recovery rates.

1994 ◽  
Vol 353 ◽  
K. Noshita ◽  
T. Nishi ◽  
M. Matsuda

AbstractHydrogen gas is generated from cementitious waste forms by radiolysis of water. In the case of low level radioactive waste, gas yields have been confirmed to be sufficiently low by irradiation experiments. However, studies have suggested that the hydrogen generation rate in cementitious waste forms is larger than the rate calculated from the g-value (H2 yields for 100eV absorbed). In this paper, the factors that increase the gas generation were investigated quantitatively. Two factors were identified, the effect of an organic diethylene glycol which reacts with hydrogen radicals to produce hydrogen, and the effect of electrons generated in the cementitious matrix which decompose water to hydrogen. The hydrogen generation rate was confirmed to drop less than the rate calculated from the g-value when these factors were eliminated.

2006 ◽  
Vol 519-521 ◽  
pp. 1335-1340 ◽  
Makoto Kobashi ◽  
Naoyuki Kanetake

Aluminum foam is a class of porous materials; in which closed pores are produced by a gas generation in liquid (or semi-liquid) aluminum. Aluminum foams are, generally, fabricated by heating a foamable precursor (a powder compact consisting of aluminum and TiH2 powders). Decomposition of TiH2, which is followed by a hydrogen gas release, produces bubbles in molten aluminum. In this research, aluminum foam was fabricated with the help of a chemical exothermic reaction. Titanium and boron carbide (B4C) powders were blended in the Al-TiH2 precursor as reactive powder elements. When one end of the precursor was heated, a strong exothermic reaction between titanium and B4C took place (3Ti + B4C 􀃆 2TiB2 +TiC + 761KJ), and the neighboring part of the precursor was heated by the heat of reaction. Hence, once the reaction happens at the end of the precursor, it propagates spontaneously throughout the precursor. The blowing process takes place at the same time as the reaction because aluminum melts and TiH2 decomposes by the heat of reaction. The advantage of this process is that the energy to make aluminum foam is not necessarily supplied form the external source, but generated form inside of the precursor. Therefore the blowing process is self sustainable (Self-Blowing Process). In this work, the effect of processing parameters on the Self-Blowing Process was observed. The processing parameters we focused on were blending ratio of the starting powders (aluminum, TiH2, titanium, B4C) and heating methods.

1995 ◽  
Vol 32 (9) ◽  
pp. 912-920 ◽  
Toshiaki MATSUO ◽  
Takashi NISHI ◽  
Masami MATSUDA ◽  

2006 ◽  
Vol 43 (10) ◽  
pp. 1287-1288 ◽  
Takao KOJIMA ◽  
Kentaro TAKAYANAGI ◽  
Ryoichi TANIGUCHI ◽  
Shuichi OKUDA ◽  
Satoshi SEINO ◽  

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