Heat-Up Colloidal Synthesis of Shape-Controlled Cu-Se-S Nanostructures—Role of Precursor and Surfactant Reactivity and Performance in N2 Electroreduction

Abstract

Copper selenide-sulfide nanostructures were synthesized using metal-organic chemical routes in the presence of Cu- and Se-precursors as well as S-containing compounds. Our goal was first to examine if the initial Cu/Se 1:1 molar proportion in the starting reagents would always lead to equiatomic composition in the final product, depending on other synthesis parameters which affect the reagents reactivity. Such reaction conditions were the types of precursors, surfactants and other reagents, as well as the synthesis temperature. The use of ‘hot-injection’ processes was avoided, focusing on ‘non-injection’ ones; that is, only heat-up protocols were employed, which have the advantage of simple operation and scalability. All reagents were mixed at room temperature followed by further heating to a selected high temperature. It was found that for samples with particles of bigger size and anisotropic shape the CuSe composition was favored, whereas particles with smaller size and spherical shape possessed a Cu2−xSe phase, especially when no sulfur was present. Apart from elemental Se, Al2Se3 was used as an efficient selenium source for the first time for the acquisition of copper selenide nanostructures. The use of dodecanethiol in the presence of trioctylphosphine and elemental Se promoted the incorporation of sulfur in the materials crystal lattice, leading to Cu-Se-S compositions. A variety of techniques were used to characterize the formed nanomaterials such as XRD, TEM, HRTEM, STEM-EDX, AFM and UV-Vis-NIR. Promising results, especially for thin anisotropic nanoplates for use as electrocatalysts in nitrogen reduction reaction (NRR), were obtained.

Nanosynthesis and Characterization of Cu1.8Se0.6S0.4 as a Potential Cathode for Magnesium Battery Applications

“…Thus, the graphical representation of ( h ν F km ) 2 against h ν can be used to evolve the band gap energy by extrapolating the linear portion to the X -axis ( h ν = 0), as manifested in Figure . It has been found that the band gap of Cu 1.8 Se 0.6 S 0.4 nanopowder is about 1.23 eV (Figure a), which agrees with many previous reports. − On the other hand, the band gap energy of Cu 1.8 Se 0.6 S 0.4 is about 3.07 eV (Figure b), which is attributed to the presence of PVDF, which has a large band gap (5.66 eV) − leading to widening of the band of the composite. Here, Cu 1.8 Se 0.6 S 0.4 has been mixed and filled inside the PVDF, and now, the band gap is the band gap of the whole composite (mixture) and not for Cu 1.8 Se 0.6 S 0.4 only.…”

“…19,20 Several transitional metal chalcogenides have been explored as cathodes, including molybdenum sulfide (MoS 2 ), 21 titanium sulfide (TiS 2 ), 19 vanadium sulfide (VS 2 ), 22 copper selenide (CuSe), 23 copper indium sulfide-selenide (CIS/Se), copper sulfides (Cu 7.2 S 4 ), 24 copper antimony selenide sulfide (CuSbSe x S 2−x ), 25 and copper selenide-sulfide (CuSeS). 26,27 More recently, CuSe witnessed few reports as a promising cathode for rechargeable magnesium-ion batteries (RMB). 23,28 The significant advantage of CuSe is that it depends on the displacement reaction mechanism, which is very favorable in boosting the battery's performance.…”

“…This provides a distinct nanostructured network that creates ample space for the intercalation of Mg ions. This finally boosts the whole battery’s performance. , Several transitional metal chalcogenides have been explored as cathodes, including molybdenum sulfide (MoS 2 ), titanium sulfide (TiS 2 ), vanadium sulfide (VS 2 ), copper selenide (CuSe), copper indium sulfide-selenide (CIS/Se), copper sulfides (Cu 7.2 S 4 ), copper antimony selenide sulfide (CuSbSe x S 2– x ), and copper selenide-sulfide (CuSeS). , …”

Colloidal Processing of Mn3O4-Carbon Nanotube Nanocomposite Electrodes for Supercapacitors

“…Colloidal methods are widely used for the fabrication of advanced nanomaterials and nanocomposites [ 1 , 2 , 3 ]. The use of surfactants for colloidal nanofabrication allows efficient control of particle size and prevention of their agglomeration [ 4 , 5 , 6 , 7 ].…”

Assembly of Hydrophobic ZIF-8 on CeO2 Nanorods as High-Efficiency Catalyst for Electrocatalytic Nitrogen Reduction Reaction

“…As a potential alternative to Haber–Bosch, electrocatalytic nitrogen reduction reaction (NRR) is a green and sustainable method to produce NH 3 [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. As we all know, the electrocatalytic NRR process, as opposed to the simple two-electron reaction mechanism of hydrogen evolution reaction (HER), includes numerous multiphase reactions involving six protons, six electrons, and one N 2 and a complicated mass transfer process [ 8 ].…”