Room temperature sequential ionic deposition (SID) of Ag₂S nanoparticles on TiO₂ hierarchical spheres for enhanced catalytic efficiency

Abstract

Porous TiO 2 hierarchical spheres with high surface area synthesized via a solvothermal method were successfully modified with an Ag 2 S co-catalyst by a sequential ionic deposition (SID) method at room temperature. The presence of Ag 2 S facilitated efficient charge separation, thus reducing recombination and enhancing the photocatalytic activity of the photocatalyst. The enhanced photocatalytic performance was demonstrated by water splitting where hydrogen (H 2 ) gas was produced at an evolution rate of 708 mmol h À1 g À1 and methyl orange was degraded with a rate constant of 0.018 min À1 . This is the first time that photocatalytic water splitting using a suspension system has been demonstrated on a Ag 2 S/TiO 2 hierarchical heterostructure and the material shows stability in its photocatalytic performance despite being recycled several times. The composite material presents properties which are highly promising for the generation of clean energy and environmental clean up applications. Scheme 1 (a) Schematic illustration of the SID process in each cycle of Ag 2 S deposition and (b) changes in the color of the composite with an increasing number of cycles. 6510 | J. Mater. Chem. A, 2015, 3, 6509-6516 This journal is

Photoexcited Properties of Tin Sulfide Nanosheet-Decorated ZnO Nanorod Heterostructures

“…The broader absorption spectrum and lower absorption edge energy indicated that the ZnO–Sn 2 S 3 nanorod heterostructures had superior optical absorption capability under light illumination. It has been reported that the construction of a heterostructure by coupling with the visible light sensitizers similarly extended the optical absorption edge of the wide-bandgap oxides in other material systems (i.e., ZnO–CdS, TiO 2 –Ag 2 S, and SnO 2 –Fe 2 O 3 ) [23–25]. Figure 4b displays the room-temperature PL spectra of the ZnO and ZnO–Sn 2 S 3 nanorods.…”

Photosensitization of TiO2 nanofibers by Ag2S with the synergistic effect of excess surface Ti3+ states for enhanced photocatalytic activity under simulated sunlight

“…used sequential ionic deposition to fabricate Ag 2 S NPs on TiO 2 hierarchical spheres. Enhanced simulated solar light driven photocatalytic performance was demonstrated by water splitting with hydrogen production at 708 μmolh −1  g −1 and photodegradation of methyl orange with pseudo-first order rate constant of 0.018 min −1   39 .…”

SILAR BiOI‐Sensitized TiO2 Films for Visible‐Light Photocatalytic Degradation of Rhodamine B and 4‐Chlorophenol

“…Immobilisation of the TiO 2 film simplifies the separation of the photocatalystp ost-use, and reducest he chance that any nanoscale materials will remain in solution-a health risk which has recently been broughtt oa ttentioni nt he literature. [34][35][36][37] While BiOI SILAR for photovoltaica pplicationsh as been previouslys tudied, [38][39][40] to the BiOI nanoplates were deposited upon af ilm of TiO 2 nanoparticles derived from ac ommercial source using as imple room temperature sequential ionic layer adsorption and reaction (SILAR) method.X -ray diffraction, X-ray photoelectron spectroscopy and electron microscopies have been used to confirm the crystal phase, chemical states of key elements and morphologyofthe BiOI nanoplate-TiO 2 composites. [31][32][33] For the purposes of photocatalysis SILARi sr elatively unexplored and relatively few examples have been reported.…”