Visible-light-driven water splitting from dyeing wastewater using Pt surface-dispersed TiO2-based nanosheets

- Pt-TNS with high specific surface is fabricated using a simple by one-pot method.
- Pt-TNS leads to obvious increase of the visible light absorption.
- Surface-dispersed Pt can effectively trap electrons to enhance the separation of charges.
- Pt-TNS exhibits excellent synergistic effects for simultaneous hydrogen production and destruction of dyestuffs.

TiO2-nanosheet (TNS) was firstly fabricated using a one-pot hydrothermal route followed with photo depositing various dosages of Pt nanoparticles over its surface. The hydrogen production performance of these as-prepared samples was assessed in triehanolamine (TEOA) aqueous solutions under visible-light irradiation. The results showed the optimal ratio of Pt: TNS was 0.5 wt %, with apparent quantum efficiency (QE) climbing 15.44%. And on this basis, it was used to H2 production simultaneous photodegradation with individual or both kinds of dyes (namely, methyl orange (MO), eosine Y (EY), methyl blue (MB) and rhedamine B (RhB)), respectively. As the figures indicated, although the rate of hydrogen production saw a steady increase in the single dye in the solution, it was outmatched by any two kinds of dyes group, which played significant positive synergism effects. In particular, when MB/EY group was added intoTEOA solution, the QE reached a peaking of 25.42% dramatically. In addition, real textile industrial wastewater was applied in this system, and the QE was 20.45%, which was 1.32 fold that of clean water. The crucial factor in improving the photocatalytic activity was that appropriate amount of functional 0D-2D Schottky barrier heterostructures were constructed. Such a novel architecture provided a large and intimate contact interface for fast interfacial photo-charges separation. The effective charge transfer from TNS to Pt was demonstrated by the significant enhancement of photocurrent responses in 0D-2D Pt-TNS composite. This work created new opportunities for designing and constructing highly efficient photocatalysts by interfacial engineering.