The Design of a New Cobalt Sulfide Nanoparticle Implanted Porous Organic Polymer Nanohybrid as a Smart and Durable Water‐Splitting Photoelectrocatalyst

Abstract

Development of an inexpensive, efficient and robust nanohybrid catalyst as a substitute for platinum in photoelectrocatalytic hydrogen production has been considered intriguing and challenging. In this study, the design and sequential synthesis of a novel cobalt sulfide nanoparticle grafted Porous Organic Polymer nanohybrid (CoS @POP) is reported and used as an active and durable water-splitting photoelectrocatalyst in the hydrogen evolution reaction (HER). The specific textural and relevant chemical properties of as-synthesised nanohybrid materials (Co O @POP &CoS @POP) were investigated by means of XRD, XPS, FTIR, C CP MAS NMR, spectroscopy, HR-TEM, HAADF-STEM with the corresponding elemental mapping, FE-SEM and nitrogen physisorption studies. CoS @POP has been evaluated as a superior photoelectrocatalyst in HER, achieving a current density of 6.43 mA cm at 0 V versus the reversible hydrogen electrode (RHE) in a 0.5 m Na SO electrolyte which outperforms its Co O @POP analogue. It was found that the nanohybrid CoS @POP catalyst exhibited a substantially enhanced catalytic performance of 1.07 μmol min cm , which is considered to be ca. 10 and 1.94 times higher than that of pristine POP and CoS , respectively. Remarkable photoelectrocatalytic activity of CoS @POP compared to Co O @POP toward H evolution could be attributed to intrinsic synergistic effect of CoS and POP, leading to the formation of a unique CoS @POP nanoarchitecture with high porosity, which permits easy diffusion of electrolyte and efficient electron transfer from POP to CoS during hydrogen generation with a tunable bandgap, that straddles between the reduction and oxidation potential of water.

Realizing Catalytic Acetophenone Hydrodeoxygenation with Palladium-Equipped Porous Organic Polymers

“…On Pd@Al 2 O 3 , we achieved 75% AP conversion and 3% selectivity to EB after 60 min reaction time and TOF was 3.80 min -1 . The higher TOF of Pd@Ph-POP could be assigned to the higher oxygen content, which helps in homogeneous dispersion of Pd nanoparticles and presence of electron-rich Pd formed through the strong electronic interaction between Pd and O atoms in the polymer framework which had been confirmed from comparison of XPS analysis of bare Ph-POP and Pd@Ph-POP (Figure S13, SI), 14 facilitating hydrogenation over the electron-enriched metallic Pd. 13 The superior selectivity towards EB of Pd@Ph-POP (100%) than Pd@Al 2 O 3 (3%) under similar reaction conditions could correspond to the strong effect of the hydroxyl rich polymer support acidity promoting dehydration route of PhE to EB transformation, as evidenced from higher surface acid strength of Ph-POP (1.603 mmol/g) compared to alumina (0.936 mmol/g) determined from NH 3 -TPD measurement which is in good agreement with the work reported by Chen et al 12 lectivity was observed at above 60 o C which could be assigned to appearance of ethylcyclohexane (EC) as side product triggered by the over hydrogenation of the benzene ring (Figure S14).…”

Amorphous Boron Dispersed in LaCoO3 with Large Oxygen Vacancies for Efficient Catalytic Propane Oxidation

“…The O 1s XPS spectra (Figure 4 B) are consisted as having three kinds of oxygen species. Peak O α located at 529.0 eV corresponds to lattice oxygen species; peak O β at 531.3 eV is contributed by the presence of absorbed oxygen species; peak O γ at 532.5 eV is assigned to the absorbed H 2 O [32] . The apparently largest amount of absorbed oxygen species on LCB‐7 suggests it has the most O v .…”

Design and Catalytic Application of Functional Porous Organic Polymers: Opportunities and Challenges

“…CoS x @POP has been evaluated as a superior photoelectrocatalyst in HER, achieving a current density of 6.43 mA cm −2 at 0 V versus the reversible hydrogen electrode (RHE) in a 0.5 m Na 2 SO 4 electrolyte which outperforms its Co 3 O 4 @POP analogue. (Scheme ) . The BET surface areas of Co 3 O 4 @POP and CoS x @POP were found to be 582 and 489 m 2 g −1 respectively.…”