Exploring the activation pathway of photo-induced electrons in facets-dependent I-doped BiOCl nanosheets for PCPNa degradation.

Electrons can degrade pentachlorphenate sodium (PCPNa) directly or activate molecular oxygen to produce·O2-and ·OH for its degradation. However, less work has been performed to control such two kinds of reaction pathway by modifying BiOCl. Herein, we firstly regulated the reaction pathway between electrons and PCPNa by adjusting the amount of surface oxygen vacancies (OVs) and surface adsorbed hydroxyl groups in I-doped BiOCl exposed with different facets. OVs on (001) facets-exposed I-doped BiOCl enabled large amount of PCPNa to adsorb on its surface and facilitated the direct reaction between electrons and PCPNa. In contrary, more surface adsorbed hydroxyl groups and oxygen on (010) facets-exposed I-doped BiOCl can retard the direct reaction between electrons and PCPNa via lowering the adsorption of PCPNa and increasing the activation of molecular oxygen by electrons. Although more·O2-and ·OH generated in I-doped (010)-facets exposed BiOCl, I-doped (001)-facets exposed BiOCl exhibited better photocatalytic activity. We proposed that the direct reaction between electrons and PCPNa can enhance the utilization efficiency of photogenerated electrons and improve photocatalytic degradation efficiency of PCPNa.

Hydrofluoric Acid Controlled TiO2 Phase Transformation from Rutile to Anatase at Room Temperature and Their Photocatalytic Performance.

In this study, we first present rutile TiO2 superstructures could be successfully transformed into anatase TiO2 nanoparticles at room temperature by adjusting the amount of hydrofluoric acid (HF) used in aqueous solution. Photocatalytic experiments demonstrated that the as prepared anatase TiO2 exhibited better photocatalytic performance than that of rutile TiO2. We further studied the photocatalytic degradation of RhB on different TiO2 via active species trapping experiments and confirmed that the presence of surface F- on TiO2 was beneficial for the formation of *OH, which was thought to be mainly responsible for the enhancement of photocatalytic performance.

Bifunctional 3D POM-based coordination polymers for improved pseudocapacitance and catalytic oxidation performance.

Developing novel high-efficiency supercapacitors as energy storage devices to solve the energy crisis is of vital significance. Meanwhile, designing highly active and selective oxidation catalysts for various sulfides is desirable but still a big challenge. To work out these problems, three novel 3D POM-based coordination polymers (POMCPs), formulated as [{Ag6(pytz)4}{SiMo12O40}] (1), [{Cu3(pytz)4}{SiMo12O40}]·5.5H2O (2) and [{Cu6(pytz)6}{SiMo12O40}]·2H2O (3) (pytz = 4-(5-(4-pyridyl)-1H-tetrazole)), are successfully prepared via a one-step synthetic strategy by changing different temperatures under hydrothermal or solvothermal conditions. In compounds 1 and 2, {SiMo12}, as 9-capped and 2-capped polyoxoanions, are engaged among the 2D Ag/Cu-organic sheets to generate the novel 3D POM-based coordination polymers. In addition, 1D Cu-organic chains are combined with 3-capped {SiMo12} polyoxoanions to construct 2D POM-based coordination polymers in 3. To our delight, as electrode materials for supercapacitors, the three compounds exhibit excellent specific capacitances of 261.76 F g-1, 248.82 F g-1 and 156.47 F g-1 at 0.5 A g-1, respectively. Besides, they can effectively and selectively catalyze the oxidation of various sulfides to sulfoxides.

From nanoplates to microtubes and microrods: a surfactant-free rolling mechanism for facile fabrication and morphology evolution of Ag2S films.

By a simple and facile wet-chemistry technique without any surfactant, various shapes of Ag(2)S crystals--including leaflike pentagonal nanoplates, crinkly nanoscrolls, hexagonal prismlike microtubes, and microrods--were fabricated in situ on a large-area silver-foil surface separately. Detailed experiments revealed that the Ag(2)S nanoplates were formed just by immersing the silver foil in a sulfur/ethanol solution at room temperature and atmospheric pressure, and they subsequently rolled into nanoscrolls and further grew into microtubes and microrods under solvothermal conditions. Inspired by the natural curling of a piece of foliage, we proposed a surfactant-free rolling mechanism to interpret the observed morphological evolution from lamellar to tubular structures. Based on these simple, practical, and green chemical synthetic routes, we can easily synthesize lamellar, scrolled, tubular, and clubbed Ag(2)S crystals by simply adjusting the reaction temperature, pressure, and time. It is very interesting to note that the current rolling process is quite different from the previous reported rolling mechanism that highly depends on the surfactants; we revealed that the lamellar Ag(2)S could be rolled into tubular structures without using any surfactant or other chemical additives, just like the natural rolling process of a piece of foliage. Therefore, this morphology-controlled synthetic route of Ag(2)S crystals may provide new insight into the synthesis of metal sulfide semiconducting micro-/nanocrystals with desired morphologies for further industrial applications. The optical properties of the pentagonal Ag(2)S nanoplates/film were also investigated by UV/Vis and photoluminescence (PL) techniques, which showed large blue-shift of the corresponding UV/Vis and PL spectra.

Efficient visible light driven photocatalytic removal of RhB and NO with low temperature synthesized In(OH)xSy hollow nanocubes: a comparative study.

In this work, we report that RhB and NO could be effectively removed under visible light with hollow In(OH)xSy nanocubes fabricated at a low temperature of 80 °C. The photocatalytic experiments revealed that these low temperature synthesized hollow In(OH)xSy nanocubes were more efficient than P25 and In(OH)xSy counterpart hydrothermally synthesized at 180 °C (In(OH)xSy-180). The porous structures, larger surface area, and new valence band of low temperature synthesized hollow In(OH)xSy nanocubes were thought to account for their superior photocatalytic activity. Among all the In(OH)xSy samples, the one with original S/In ratio of 0.500 in synthetic solution exhibited the highest photocatalytic removal efficiencies of RhB, while the other with original S/In ratio of 1.000 removed NO most efficiently. We systematically studied the photocatalytic process of RhB on In(OH)xSy and analyzed their different photocatalytic performances on removing RhB and NO. This study reveals that these hollow In(OH)xSy nanocubes are promising for environmental remediation.

A green route to prepare metal-free phthalocyanine crystals with controllable structures by a simple solvothermal method.

Exploring the environmentally friendly and low-cost synthesis strategies of phthalocyanine (Pc) crystals in just one step is an absolute challenge. The solvothermal synthesis of phthalocyanine crystals shows the advantages of high-quality crystalline products, facile reaction and purification, and low cost. Nevertheless, only a few metal phthalocyanine crystals have been successfully synthesized via solvothermal reactions. In this study, we found that the crystalline ß metal-free phthalocyanine needles could be directly prepared via the tetrapolymerization of phthalodinitrile catalyzed by DBU in solvothermal reactions. Similar to the preparation of ß-phthalocyanine crystals, the α metal-free phthalocyanine crystals with the specific multiply-laminated structures can be obtained through solvothermal reactions assisted by DBN. SEM characterization showed that the individual ß metal-free phthalocyanine has a well-defined quadrangular shape with smooth faces. However, the α metal-free phthalocyanine exhibits a distinctive undulating surface morphology. Both phthalocyanines showed satisfactory thermal stability (from room temperature to about 300 °C), excellent resistance to acid/alkali solution, and fast photoelectric response properties (order of magnitude of response time, 10-6 s) as tested by TG-DSC and TPV, respectively. It is noted that ethanol was used as the reaction medium and the resulting phthalocyanine crystals can be facilely purified using hot ethanol to dissolve the impurities adsorbed on the surfaces of phthalocyanine crystals. Compared to the traditional methods, no re-crystallization operation was carried out for our method. To the best of our knowledge, this is the first report on the solvothermal synthesis of metal-free phthalocyanine crystals with controllable crystal form adjusted by DBU/DBN in one step.

The efficient, fast and facile decolorization of organic dyes homogeneously catalyzed by iron octacarboxylic phthalocyanine.

To remove the harmful dye contaminants via an efficient, facile and low energy consumption route is a grave challenge in current chemical industry. Though the great progresses of TiO2 photocatalysis and enzymatic degradation have been witnessed, the strategy for satisfying the above requirements is still worth exploring. Herein, we develop a biomimetic catalysis strategy for the fast decolorization of organic dyes catalyzed by iron octacarboxylic phthalocyanine (FeOCPc) complexes assisted with tert-butyl hydroperoxide (BuOOH). Methyl orange (MO) and methylene blue (MB) were used as the model pollutants and experimental results show that the decolorization degree of 25 mg/L MO could achieve 100% within 20 min and 80% for 25 mg/L MB within 30 min. The molar ratio for FeOCPc/MO and FeOCPc/MB is 0.146 and 0.142, respectively. Interestingly, other than the high-valent iron-oxygen active species, tert-butyl peroxyl radicals and hydroxyl radicals were detected as the active species generated during the catalytic oxidation by the electron paramagnetic resonance (EPR) measurement. This work not only provides a distinctive biomimetic catalysis system of FeOCPc-BuOOH for the fast bleaching of dye pollutants, but also proposes the new insight on a mechanism based on the cooperation catalysis of iron-oxygen active species, tert-butyl peroxyl radicals and hydroxyl radicals.

A simple and facile bioinspired catalytic strategy to decolorize dye wastewater by using metal octacarboxyphthalocyanine particles.

To explore the simple, facile, environmental friendly and low cost catalytic technique to decolorize harmful dye contaminants in solution and understand the mechanism is an interesting and practical research. In this paper, we provide a highly efficient and convenient method for fast decolorization of dyes (methylene blue and rhodamine B) in aqueous solution catalyzed by iron octacarboxyphthalocyanine (FeOCPc) or cobalt octacarboxyphthalocyanine (CoOCPc). Compared to the traditional methods, our method is very simple. The 30 mg/L methylene blue could be decolorized almost absolutely less than 30 min just by dispersing FeOCPc powders into the dye solution. The decolorization of rhodamine B at high concentration (30 mg/L) could be achieved to 100% decolorization degree less than 20 min in the presence of FeOCPc and tert-butyl hydroperoxide (BuOOH). Moreover, the ESR and HPLC-MS measurement were performed to determine the active radicals and various intermediates in decolorization processes and the possible catalytic mechanism was proposed. It is noted that both FeOCPc and CoOCPc catalysts show the different catalytic oxidation behaviors depending on the oxidant (O2 or BuOOH). Our investigation provides a novel, low cost and convenient strategy to purify the environmental pollutions.