A black Ti 3+ -doped single-crystal TiO 2 (Ti 3+ /TiO 2 ) was one-pot synthesized by treating metal Ti in an ionic liquid containing LiAc and HAc under mild ionothermal conditions. The ionic liquid(1-methyl-imidazolium tetrafluoroborate) supplied an environment enriched with fluoride ions for dissolving titanium foil at ionothermal condition, followed by reducing protons in acetic acid to form Ti 3+ ions, leading to Ti 3+ -doped single-crystal TiO 2 in black powder. EPR and XPS results indicated the high-concentrations of both Ti 3+ -dopants and oxygen vacancies. The Ti 3+ incorporated into TiO 2 lattice could narrow the energy band gap of TiO 2 via forming intermediate energy levels, leading to the visible photocatalyst. Meanwhile, the oxygen vacancies could inhibit the photoelectron-hole recombination. As expected, such a black Ti 3+ /TiO 2 exhibited high activity in photocatalytic degradation of organic pollutants and water splitting for H 2 production under irradiation with visible lights and/or simulated solar lights.

Ultrafast excited‐state decay and intrinsic charge carrier recombination restrain the photoactivity enhancement for solar‐to‐H2 production. Here, a CdS‐fullerene/graphene (CdS‐F/G) photocatalyst is synthesized for enhancing visible‐light‐driven hydrogen generation from earth‐abundant water. The CdS‐F/G shows ultrafast interfacial electrons/holes transfer and holes self‐trapping process in photocatalysis. The in‐situ dynamic study from transient absorption spectroscopy reveals the sub‐microsecond‐lived excited states (≈172.6 ns), interfacial electron transfer (≈30.3 ps), and hole trapping (≈44.0 ps) in the CdS‐F/G photocatalyst. The efficient active species transportation and prolonged lifetime significantly enhance the charge separation state survival, increasing the photoactivity and photostability. Consequently, visible‐light activity enhancement (>400%) of H2 evolution reaction (HER) is obtained at the CdS‐F/G photocatalyst with high stability (>36 h). The 127.2 µmol h−1 g−1 performance corresponding to a quantum efficiency of 7.24% at 420 nm is not only higher than the case of pristine CdS (29.2 µmol h−1 g−1) but also much higher than that of CdS‐Pt photocatalyst (73.8 µmol h−1 g−1). The cost‐effective CdS‐F/G photocatalyst exhibits a great potential for sustainable and high‐efficiency photocatalytic water splitting into clean energy carriers. Moreover, the optimized electronic structure associated with interfacial electrons/holes transfer and holes self‐trapping promotes overall water splitting for H2 and O2 generation.

Hybrid mesoporous periodic organosilicas (Ph-PMOs) with phenylene moieties embedded inside the silica matrix were used as a heterogeneous catalyst for the Ullmann coupling reaction in water. XRD, N2 sorption, TEM, and solid-state NMR spectroscopy reveal that mesoporous Ph-PMO supports and Pd/Ph-PMO catalysts have highly ordered 2D hexagonal mesostructures and covalently bonded organic-inorganic (all Si atoms bonded with carbon) hybrid frameworks. In the Ullmann coupling reaction of iodobenzene in water, the yield of biphenyl was 94%, 34%, 74% and for palladium-supported Ph-PMO, pure silica (MCM-41), and phenyl-group-modified Ph-MCM-41 catalysts, respectively. The selectivity toward biphenyl reached 91% for the coupling of boromobenzene on the Pd/Ph-PMO catalyst. This value is much higher than that for Pd/Ph-MCM-41 (19%) and Pd/MCM-41 (0%), although the conversion of bromobenzene for these two catalysts is similar to that for Pd/Ph-PMO. The large difference in selectivity can be attributed to surface hydrophobicity, which was evaluated by the adsorption isotherms of water and toluene. Ph-PMO has the most hydrophobic surface, and in turn selectively adsorbs the reactant haloaryls from aqueous solution. Water transfer inside the mesochannels is thus restricted, and the coupling reaction of bromobenzene is improved.

In the present work, highly efficient and stable Au/CeO2-TiO2 photocatalysts were prepared by a microwave-assisted solution approach. The Au/CeO2-TiO2 composites with optimal molar ratio of Au/Ce/Ti of 0.004:0.1:1 delivered a remarkably high and stable NO conversion rate of 85% in a continuous flow reactor system under simulated solar light irradiation, which far exceeded the rate of 48% over pure TiO2. The tiny Au nanocrystals (∼1.1 nm) were well stabilized by CeO2 via strong metal-support bonding even it was subjected to calcinations at 550 °C for 6 h. These Au nanocrystals served as the very active sites for activating the molecule of nitric oxide and reducing the transmission time of the photogenerated electrons to accelerate O2 transforming to reactive oxygen species. Moreover, the Au-Ce(3+) interface formed and served as an anchoring site of O2 molecule. Then more adsorbed oxygen could react with photogenerated electrons on TiO2 surfaces to produce more superoxide radicals for NO oxidation, resulting in the improved efficiency. Meanwhile, O2 was also captured at the Au/TiO2 perimeter site and the NO molecules on TiO2 sites were initially delivered to the active perimeter site via diffusion on the TiO2 surface, where they assisted O-O bond dissociation and reacted with oxygen at these perimeter sites. Therefore, these finite Au nanocrystals can consecutively expose active sites for oxidizing NO. These synergistic effects created an efficient and stable system for breaking down NO pollutants. Furthermore, the excellent antisintering property of the catalyst will allow them for the potential application in photocatalytic treatment of high-temperature flue gas from power plant.