Coordination Polymer Derived NiS@g-C₃N₄ Composite Photocatalyst for Sulfur Vacancy and Photothermal Effect Synergistic Enhanced H₂ Production

Abstract

To obtain the photocatalyst composed by sulfur vacancies rich NiS and graphitic carbon nitride (g-C3N4), a simple method has been found for using coordination polymer as precursor. Based on this strategy, an effective composite photocatalyst, NiS@g-C3N4, is synthesized successfully through the calcination of a Ni2+ based coordination polymer with 2-mercapto-5-propylpyrimidine as ligand. In this photocatalyst, the NiS nanoparticles with small size disperse evenly in 2-mercapto-5-propylpyrimidine derived g-C3N4. Electron paramagnetic resonance (EPR) suggests there are a lot of sulfur vacancies in NiS@g-C3N4. NiS@g-C3N4 exhibits intensive adsorption in the near-infrared region, which endows NiS@g-C3N4 with promising photothermal effect. With a 980 nm laser as light source (0.44 W·cm–2), the aqueous dispersion of NiS@g-C3N4 exhibits a temperature elevation of 56.7 °C with photothermal conversion efficiency of 58.2%. Under irradiation of simulated solar light, without Pt co-catalyst, NiS@g-C3N4 possesses a promising photocatalytic H2 production rate, with the value 31.3 mmol·g–1·h–1. In five cycles of reactions for 30 h, the H2 production rate remains constant. The synergy between sulfur vacancy and photothermal effect of NiS play significant roles in the enhancement of H2 production property.

Bio-templated formation of defect-abundant VS2 as a bifunctional material toward high-performance hydrogen evolution reactions and lithium−sulfur batteries

“…It is evident that the bio-templated VS 2 sample displays a resonance signal at g = 2.00 ( Fig. S5), suggesting the presence of sulfur vacancy [31] . These characterizations corroborate the defect-abundant feature of bio-templated VS 2 .…”

Boosting photocatalytic hydrogen production from water by photothermally induced biphase systems

“…The design exhibits biphase interfaces of self-generated steam/photocatalyst loaded on the charred wood substrates/hydrogen gas. Our strategy of the photothermally induced biphase interfacial feature differs from previous studies of the room-temperature vapor in moisture environment to reduce the catalysts corrosion (the humidity was realized through a complex microfluidic microreactor 8 – 10 , convection effect 11 , and hydrophobic effect 12 ) and plasmonic thermal effects 13 and near-infrared photothermal effects 14 , 15 in the triphase interfaces of liquid water/photocatalyst/hydrogen. This photothermal–photocatalytic biphase system kinetically lowers the hydrogen gas’s transport resistance by nearly two orders of magnitude to allow the easy escape of hydrogen gas from the system.…”

Carbon Dots-Decorated Bi2WO6 in an Inverse Opal Film as a Photoanode for Photoelectrochemical Solar Energy Conversion under Visible-Light Irradiation

“…Among the photoactive materials, transition metal sulfides (such as CdS [19,20], Znln 2 S 4 [21,22] and iron group elements like Fe-, Ni- and Co-based sulfides [23,24,25,26,27]) with a relatively narrow bandgap are sensitive to most of the visible wavelength region. However, the photogenerated holes tend to oxidize the catalyst itself, rather than water, in the absence of sacrificial reagent, resulting in photocorrosion.…”