Colloidal Synthesis and Photocatalytic Performance of Size‐Controllable Solid or Hollow CuInSe₂ Nanocrystals

Abstract

Morphology evolution dependence on reaction time has been investigated to find a way to overcome polydispersity of the chalcopyrite CuInSe2 nanocrystals (NCs). A building–crumbling process is presented to understand the formation of small NCs. By carefully controlling magnetic stirring, ligand content, and duration, the polydispersity is fundamentally improved; thus solid and hollow spherical NCs and quantum dots can be easily obtained with tunable sizes. It is proposed that the NCs undergo Ostwald ripening induced morphology evolution from solid to hollow NCs. The photoelectric properties and photocatalytic activity have been investigated with TiO2 nanotube array based photoelectrodes. A maximum saturation photocurrent of 12.6 mA cm−2 has been achieved, and a structure‐dependent photocatalytic property has also been confirmed by using methyl orange as a model pollutant.

Compound Copper Chalcogenide Nanocrystals

“…Table shows the results of the photodegradation tests found in the literature using Cu chalcogenides. The photodegradation of dyes and other organic molecules having an optical fingerprint was tested using a variety of Cu chalcogenide compositions and shapes, including CuS NCs, , CuS nanotubes, , CuS hierarchical nanostructures, ,, CuS, Cu 2 S, and Cu 1.8 S nanostructured flowers, ,, Cu 2 S microsponges, CuS nanostructures, ,− Cu 2 S NPs, − ZCIS NPs, ZCIS nanorods, CuSe nanoflakes, solid and hollow CISe NPs, Cu 2 Se nanowires, Cu 2 FeSnS 4 nanostructured spheres, CuSe 1− x S x nanoflakes, and Cu 2 ZnGeS 4 NCs . Interband materials, such as Sn-doped CGS and CIS NCs and Cr-doped CGS, have also been studied and are a particularly interesting class of materials, which have enhanced performances mediating dye photodegradation.…”

Superstructural Ordering in Hexagonal CuInSe2 Nanoparticles

“…3,4 This renders CuInSe 2 outstanding for several important optoelectronic applications, such as PVs, 5−8 light-emitting diodes (LEDs), 3 and photocatalytic H 2 generation. 9 For instance, chalcopyrite Cu(In,Ga)Se 2 thin-film solar cell recently reached the record efficiency of 22.8%. 10 Nevertheless, this PV cell was fabricated using high-temperature evaporation/sputtering techniques, which are vacuum-and energy-demanding processes often requiring clean room operation.…”

“…31 Other synthetic routes to hexagonal CuInSe 2 NPs typically result in a mixture of different phases. 9,32 Importantly, the few existing reports of hexagonal CuInSe 2 NPs describe them as crystallizing in the wurtzite hexagonal cell with only one metal atomic site, which implies a mixing of Cu and In in the same atomic site. Herein, we present a gramscale synthesis of high-quality CuInSe 2 nanoparticles with welldefined hexagonal plate-like morphology.…”

“…Bulk ternary CuInSe 2 semiconductor with chalcopyrite structure has a direct band gap of 1.04 eV and a high absorption coefficient of ≈10 –5 cm –1 . , This renders CuInSe 2 outstanding for several important optoelectronic applications, such as PVs, − light-emitting diodes (LEDs), and photocatalytic H 2 generation . For instance, chalcopyrite Cu(In,Ga)Se 2 thin-film solar cell recently reached the record efficiency of 22.8% .…”

“…For example, only three synthetic reports exist for hexagonal wurtzite CuInSe 2 NPs, the initial one by Norako and Brutchey, later by Wang and co-workers, and recently by Brutchey group . Other synthetic routes to hexagonal CuInSe 2 NPs typically result in a mixture of different phases. , …”