Water reduction on the facets of Fe(OH)₂: an experimental and DFT study

Abstract

H2 production during the transformation of Fe(OH)2 into magnetite (i.e., Schikorr reaction), has a significant impact on many environmental applications, including the long-term effectiveness of permeable reactive barriers composed of...

Spontaneous Valley Polarization in a Ferromagnetic Fe(OH)2 Monolayer

“…In experiments, layered bulk materials Co­(OH) 2 and Fe­(OH) 2 with similar structures have already been synthesized, − and thus, there is a great possibility of attaining the monolayer limitation of Fe­(OH) 2 . In our calculations, we also compared the total energies of the Fe­(OH) 2 monolayer in phases H and T and found that the former is 22 meV per unit cell lower than the latter.…”

Unraveling Structural Carboxyl Defects in g‐C3N4 for Improved Photocatalytic H2 Evolution via Alternating Hydrogen‐Oxygen‐Plasma Treatment

“…To understand the possible mechanism of structural carboxyl defect sites promoting photocatalytic H 2 production of g‐C 3 N 4 , density‐functional theory (DFT) calculations were performed to understand the influence of carboxyl group defects on the band structure and electronic features of the carboxyl‐defect endowed g‐C 3 N 4 (H 2 ‐O 2 ‐pCN). [ 40 ] The calculated bandgap of H 2 ‐O 2 ‐pCN is lower than the original g‐C 3 N 4 due to the formation of an intermediate transition level ( Figure ). More importantly, the electronic structure was optimized greatly, as reflected by the charge distribution map of H 2 ‐O 2 ‐pCN, which obviously provided local asymmetric electron environment to promote the migration of electrons, thus served as H 2 evolution active center.…”

g‐C3N4 Nanosheet Nanoarchitectonics: H2 Generation and CO2 Reduction

“…Recently, we developed a W 2 C/W 2 N (WCN) particles modified ultrathin g-C 3 N 4 nanosheet Schottky junction via heterointerface engineering as shown in Figure 14, with the average size of tungsten carbide/ tungsten nitride (WCN) particles measured to be about 200 nm. [143] Based on the diffuse reflectance spectra obtained for the WCN particles modified g-C 3 N 4 composites (WCN/CN-25% in Figure 15a), it was obvious that the incorporation of WCN particles modified g-C 3 N 4 showed a red-shift in absorption edge (from 423 to 431 nm) and enhanced the visible light responsive-ness (400-800 nm). The estimated band gap of g-C 3 N 4 and WCN/CN-25% composites were around 2.72 and 2.66 eV, respectively (Figure 15b).…”

“…The flat band potentials of g-C 3 N 4 and WCN/CN-25% (obtained through Mott-Schottky plots in Figure 15c) measured to be around À 0.89 and À 0.63 V, respectively, and the change in Fermi levels of the composite material is attributed to the incorporation of WCN particles in g-C 3 N 4 . [143] In this WCN particles modified g-C 3 N 4 Schottky junction system, WCN particles work as the electron mediator to accept photogenerated electrons from the conduction band of g-C 3 N 4 (Figure 15d). [144][145][146][147][148][149][150] A drastically increase H 2 generation efficiency was observed for the WCN particles modified g-C 3 N 4 Schottky junction with no Pt co-catalyst addition (1024.6 μmolg À 1 h À 1 , which was about 165 times of that of pristine g-C 3 N 4 ).…”

“…[144][145][146][147][148][149][150] A drastically increase H 2 generation efficiency was observed for the WCN particles modified g-C 3 N 4 Schottky junction with no Pt co-catalyst addition (1024.6 μmolg À 1 h À 1 , which was about 165 times of that of pristine g-C 3 N 4 ). [143] Phosphide compounds can also form Schottky junctions with g-C 3 N 4 , for example, WP, FeP, CoP, Ni 2 P and NiCoP etc. Among these, tungsten phosphide (WP) incorporated ones have been considered to have excellent catalytic efficiencies, however, to construct monodispersed tungsten phosphide (WP) nanoparticles on g-C 3 N 4 is not easy.…”