Edge‐Enriched Ultrathin MoS₂ Embedded Yolk‐Shell TiO₂ with Boosted Charge Transfer for Superior Photocatalytic H₂ Evolution

Abstract

Exploring TiO 2 -photocatalysts for sunlight conversion has high demand in artificial photosynthesis. In this work, edge-enriched ultrathin molybdenum disulfide (MoS 2 ) flakes are uniformly embedded into the bulk of yolk-shell TiO 2 as a cocatalyst to accelerate photogeneratedelectron transfer from the bulk to the surface of TiO 2 . The as-formed MoS 2 /TiO 2 (0.14 wt%) hybrids exhibit a high hydrogen evolution rate (HER) of 2443 μmol g −1 h −1 , about 1000% and 470% of that of pristine TiO 2 (247 μmol g −1 h −1 ) and bulk MoS 2 decorated TiO 2 (513 μmol g −1 h −1 ). Such a greatly enhanced HER is attributed to the exposed catalytic edges of the ultrathin MoS 2 flakes with a robust chemical linkage (TiS bond), providing rapid charge transfer channels between TiO 2 and MoS 2 . The catalytic stability is promoted by the antiaggregation of the highly dispersed MoS 2 flakes in the bulk of yolk-shell TiO 2 . The exponential fitted decay kinetics of time-resolved photoluminescence (ns-PL) spectra illustrates that embedding ultrathin MoS 2 flakes in TiO 2 effectively decreases the average lifetime of PL in the MoS 2 /TiO 2 hybrids (τ ave = 4.55 ns), faster than that of pristine TiO 2 (≈7.17 ns) and the bulk MoS 2 /TiO 2 (≈6.13 ns), allowing a superior charge separation and charge trapping process for reducing water.

Spatially Separating Redox Centers on Z‐Scheme ZnIn2S4/BiVO4 Hierarchical Heterostructure for Highly Efficient Photocatalytic Hydrogen Evolution

“…Currently found photocatalytic materials for water splitting to produce H 2 are very limited. It is known that titanium dioxide (TiO 2 ), [ 3–5 ] graphitic carbon nitride (g‐C 3 N 4 ), [ 6–10 ] metal sulfides (including cadmium sulfide (CdS), and [ 11–13 ] zinc sulfur (ZnS) [ 14–16 ] are typical effective photocatalysts. However, Bi‐based semiconductor materials such as Bi 2 O 2 CO 3 , [ 17–19 ] Bi 2 MoO 6 , [ 20,21 ] Bi 2 WO 6 , [ 22,23 ] and BiOX (X = Cl, Br, and I) [ 24,25 ] as a very important type of photocatalysts only draw considerable attention lately.…”

Retorting Photocorrosion and Enhanced Charge Carrier Separation at CdSe Nanocapsules by Chemically Synthesized TiO2 Shell for Photocatalytic Hydrogen Fuel Generation

“…Among the narrow band gap semiconductors, cadmium based chalcogenides showed effective photocatalytic‐to‐hydrogen fuel generation compared to metal oxides as it possess high photo absorption in visible spectrum . In this line, cadmium selenide (CdSe) is a promising visible light driven semiconductor photocatalyst material have suitable energy gap and band edge potentials for H 2 generation via water splitting .…”

Photocatalytic degradation of methylene blue with spent FCC catalyst loaded with ferric oxide and titanium dioxide

“…Titanium dioxide (TiO 2 ) has been extensively investigated for photocatalytic reaction due to its chemical stability and lack of toxicity [16][17][18][19] . TiO 2 is a wide band gap semiconductor material (3.2 eV) [20][21][22][23] . In photocatalytic reaction, the charge carrier of the TiO 2 is fast recombinated, which can be prevented effectively by the heterogeneous structures (with the narrow band gap semiconductor materials) 24,25 .…”