Highly Efficient Visible Light-Induced O2 Generation by Self-Assembled Nanohybrids of Inorganic Nanosheets and Polyoxometalate Nanoclusters

Abstract

Unusually high photocatalytic activity of visible light-induced O2 generation can be achieved by electrostatically-derived self-assembly between exfoliated Zn-Cr-LDH 2D nanosheets and POM 0D nanoclusters (W7O246− and V10O286−) acting as an electron acceptor. This self-assembly can provide a high flexibility in the control of the chemical composition and pore structure of the resulting LDH-based nanohybrids. The hybridization with POM nanoclusters remarkably enhances the photocatalytic activity of the pristine Zn-Cr-LDH, which is attributable to the formation of porous structure and depression of charge recombination. Of prime interest is that the excellent photocatalytic activity of the as-prepared Zn-Cr-LDH-POM nanohybrid for visible light-induced O2 generation can be further enhanced by calcination at 200 °C, leading to the very high apparent quantum yield of ∼75.2% at 420 nm. The present findings clearly demonstrate that the self-assembly of LDH–POM is fairly powerful in synthesizing novel LDH-based porous nanohybrid photocatalyst for visible light-induced O2 generation.

CdS-pillared CoAl-layered double hydroxide nanosheets with superior photocatalytic activity

“…1a). The powder XRD patterns of materials are shown in A c c e p t e d M a n u s c r i p t 8 definite loading amount of CdS for such a pillared structure suggests that the nanohybrid's composition is dependant on the surface charge ratio of the guest CdS nanoparticle to the host LDHs nanosheet, as previously reported [21]. As displayed in Fig.…”

“…A c c e p t e d M a n u s c r i p t 4 well-developed nanohybrids assembled by the exfoliated titanate nanosheets and oxide nanoparticles [10][11][12][13]20], the reports on the materials fabricated by the exfoliated LDH nanosheets and sulfide nanoparticles are very rare [14,21]. In this work, a new CdS-pillared CoAl-LDH nanohybrid was prepared by simply mixing the positively charged 2D nanosheets of CoAl-LDH and the negatively charged CdS nanosol suspensions.…”

Highly efficient visible-light-driven photocatalytic hydrogen generation by immobilizing CdSe nanocrystals on ZnCr-layered double hydroxide nanosheets

“…2A). The isotherms and hysteresis behaviors of CZCs can be assigned as BDDT-type IV and IUPAC-H2 type hysteresis loop [34,35], which is characteristic of mesoporous materials having a high energy of adsorption and the presence of well-ordered pores with narrow and wide sections and interconnecting channels [25,35]. Compared with CZCs, ZnCr-LDH shows a steep adsorption branch at high p$p 0 À1 region and a sloping desorption branch, which corresponds to type H3 by IUPAC classification [34].…”

“…Garcia et al firstly reported the high photocatalytic activity of ZnCr-LDH for O 2 generation [22]. Subsequently, it was found that NiTi-LDH [23], ZnCr-LDH/graphene [24], ZnCr-LDH/ layered titanate [2], ZnCr-LDH/polyoxometates [25], and NiTi-LDH/graphene composites [26] have efficient photocatalysis for O 2 evolution. However, there are only a few reports about photocatalytic water splitting into H 2 .…”

“…As mentioned above, the history of LDH-based photocatalysts is very short. LDH-based nanohybrids with photocatalytic activity are underdeveloped [25]. To the best of our knowledge, there is no report regarding the application of CdSe-LDHs on the photocatalytic H 2 production.…”