Activate Fe₃S₄ Nanorods by Ni Doping for Efficient Dye-Sensitized Photocatalytic Hydrogen Production

Abstract

Developing suitable catalysts capable of receiving injected electrons and possessing active sites for hydrogen evolution reaction (HER) is the key to building an efficient dyesensitized system for hydrogen production. Fe 3 S 4 is generally regarded as an inferior HER catalyst among the metal sulfide family, mainly due to its weak surface adsorption toward H atoms. In this work, we demonstrate a facile metal−organic frameworkderived method to synthesize uniform Fe 3 S 4 nanorods and active them for HER by Ni doping. Our experimental results and theoretical calculations reveal that Ni doping can greatly modify the electronic structure of Fe 3 S 4 nanorods, improving their electron conductivity and optimizing their surface adsorption energy toward H atoms. Sensitized by a commercial organic dye (eosin-Y), 1%Ni-doped Fe 3 S 4 nanorods display a high H 2 production rate of 3240 μmol g cat −1 h −1 with an apparent quantum yield of 12% under 500 nm wavelength, which is significantly higher than that of pristine Fe 3 S 4 and even higher than that of 1% Pt-deposited Fe 3 S 4 . The working mechanism of this dye-sensitized system is explored, and the effect of Ni-doping concentration has been studied. This work presents a facile strategy to synthesize metal-doped sulfide nanocatalysts with greatly enhanced activity toward photocatalytic H 2 production.

Core–Shell Structured Cu(OH)2@NiFe(OH)x Nanotube Electrocatalysts for Methanol Oxidation Based Hydrogen Evolution

“…Compared with the Cu­(OH) 2 @FeOOH precursor, Cu­(OH) 2 @Fe 1 Ni 2.5 (OH) x showed a slight peak position change, indicating the interaction between the outer nanosheet array and the inner tube. In the spectrum of Figure a for Ni 2p, the peaks at 874.16 and 856.22 eV with two obvious shakeup satellites can be attributed to Ni 2p 1/2 and Ni 2p 3/2 , respectively, corresponding to the binding energy of Ni 2+ . , The predominant O 1s peak at 534.10 eV in Figure b is related to the metal-bonded surface hydroxyl groups. ,, The peaks at 534.50 and 535.29 eV in the O 1s spectrum of the Cu­(OH) 2 NTs and Cu­(OH) 2 @FeOOH are the oxygen in the hydroxyl group (Figure S4). These results confirm that the as-prepared core–shell nanoarrays are Cu­(OH) 2 @Fe 1 Ni 2.5 (OH) x with Fe and Ni in the oxidation states of Fe 3+ and Ni 2+ , respectively.…”

“…In the spectrum of Figure 4a for Ni 2p, the peaks at 874.16 and 856.22 eV with two obvious shakeup satellites can be attributed to Ni 2p 1/2 and Ni 2p 3/2 , respectively, corresponding to the binding energy of Ni 2+ . 43,47 The predominant O 1s peak at 534.10 eV in Figure 4b is related to the metal-bonded surface hydroxyl groups. 26,53,54 The peaks at 534.50 and 535.29 eV in the O 1s spectrum of the Cu(OH) 2 NTs and Cu(OH) 2 @FeOOH are the oxygen in the hydroxyl group (Figure S4).…”

“…37−42 Therefore, transition metal based hydroxides have been regarded as some of the efficient electrocatalyst materials in electrochemical oxidation reactions. Moreover, the morphological structure, for example, nanorods, 43 nanowire, 44,45 nanoparticle, 46 nanotube, 47,48 nanodendrite, 49 and nanoflower, 50,51 have been investigated for electrocatalyst design. It has been revealed that the catalyst modified electrode microstructure with a rich porosity and high surface area is beneficial for reactant adsorption, mass transport, and product release.…”

“…Recently, transition metal based hydroxides such as Ni­(OH) 2 and FeOOH have attracted great interest in the field of electrochemical oxidation reactions (FeOOH/Ni­(OH) 2 –FeOOH/NiOOH). − Due to the chemical valence change of transition metal species, excellent electrocatalytic oxidation activity can be achieved under the alkaline electrochemical condition. − Therefore, transition metal based hydroxides have been regarded as some of the efficient electrocatalyst materials in electrochemical oxidation reactions. Moreover, the morphological structure, for example, nanorods, nanowire, , nanoparticle, nanotube, , nanodendrite, and nanoflower, , have been investigated for electrocatalyst design. It has been revealed that the catalyst modified electrode microstructure with a rich porosity and high surface area is beneficial for reactant adsorption, mass transport, and product release.…”

Interior and Surface Synergistic Modifications Modulate the SnNb2O6/Ni-Doped ZnIn2S4 S-Scheme Heterojunction for Efficient Photocatalytic H2 Evolution

“…Recently, Zhang et al synthesized Ni-doped Fe 3 S 4 photocatalysts that revealed that Ni doping could adjust the electronic property of pure Fe 3 S 4 , optimize the surface adsorption energy toward H atoms, and enhance PHE activity. 11 Moreover, Deng and co-workers prepared Ni-doped g-C 3 N 4 photocatalysts, and the experimental results showed that Ni doping could increase light absorption, narrow the band gap, and restrain the recombination of carriers, thereby enhancing PHE activity. 12 In addition, some other Ni-doped semiconductor photocatalysts were also reported to exhibit great potential for H 2 evolution.…”