Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

Characterization and photocatalytic study of tantalum oxide nanoparticles prepared by the hydrolysis of tantalum oxo-ethoxide Ta₈(μ₃-O)₂(μ-O)₈(μ-OEt)₆(OEt)₁₄

• Subia Ambreen,
• N D Pandey,
• Peter Mayer and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2014, 5, 1082–1090, doi:10.3762/bjnano.5.121

• characterized by various techniques such as TGA-DTA-DSC, UV–vis DRS, XRD, SEM, TEM, particle size analyzer (DLS) and the Brunauer–Emmett–Teller (BET) method. The band gap of the particles was calculated by using the Tauc plot. The photocatalytic activity of Ta2O5 nanoparticles was tested by the degradation of

• to its distinct properties such as large ion diffusion coefficient and high electrochromic reversibility, high dielectric constant, high refractive index, high chemical stability, large band gap [13][14][15] and photocatalytic activity for overall water decomposition and organic pollutant degradation

• (1) was isolated. When 1 was subjected to further hydrolysis it yielded nanoparticles of tantalum oxide after calcination at 750 °C for four hours. The photocatalytic activity of Ta2O5 nanoparticles was studied over the degradation of organic dye rhodamine B (RhB). Results and Discussion Tantalum

Functionalized nanostructures for enhanced photocatalytic performance under solar light

• Liejin Guo,
• Dengwei Jing,
• Maochang Liu,
• Yubin Chen,
• Shaohua Shen,
• Jinwen Shi and
• Kai Zhang

Beilstein J. Nanotechnol. 2014, 5, 994–1004, doi:10.3762/bjnano.5.113

• with well-tailored band alignment provides a powerful means to the improvement of the photocatalytic activity. In the process of our study, we have also paid special attention on the nanoscale control of the material morphology and construction of functionalized nanostructures to promote charge

• work was carried out on Ni modified mesoporous TiO2 photocatalysts [15]. It was found that Ni ions were highly dispersed in the framework of mesoporous TiO2 resulting in enhanced hydrogen production in methanol aqueous solution compared to Ni-doped particulate TiO2. The photocatalytic activity was

• found to have a close relationship with the doping amount of Ni ions and the highest activity was obtained when the amount of Ni doping was 1%. Here, the enhanced photocatalytic activity was attributed to doped Ni2+ ions which served as shallow trapping sites, preferentially trapping photoexcited holes

Enhancement of photocatalytic H₂ evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

• Weiying Zhang,
• Yuexiang Li,
• Shaoqin Peng and
• Xiang Cai

Beilstein J. Nanotechnol. 2014, 5, 801–811, doi:10.3762/bjnano.5.92

• hydroxy groups are gradually removed from GO, resulting in an increase of sp2 π-conjugated domains and defect carbons with holes for the formed RGO. The RGO conductivity increases due to the restoration of sp2 π-conjugated domains. The photocatalytic activity of EY-RGO/Pt for hydrogen evolution was

• (RGO) shows a higher activity as a semiconductor under UV irradiation [11][12]. Yeh et al. [12] reported that RGO sheets with in situ photoreduced platinum displayed a high activity for hydrogen evolution from an aqueous methanol solution. However, the RGO exhibits a very low photocatalytic activity

• characterized by a high activity for H2 evolution under visible light irradiation. Recently, to improve the photocatalytic activity for hydrogen evolution in the visible light region, EY has been employed to sensitize RGO, and the sensitized photocatalyst displays an increased photoactivity for hydrogen

Visible light photooxidative performance of a high-nuclearity molecular bismuth vanadium oxide cluster

• Johannes Tucher and
• Carsten Streb

Beilstein J. Nanotechnol. 2014, 5, 711–716, doi:10.3762/bjnano.5.83

• reported. Photocatalytic activity studies show faster reaction kinetics under anaerobic conditions, suggesting an oxygen-dependent quenching of the photoexcited cluster species. Further mechanistic analysis shows that the reaction proceeds via the intermediate formation of hydroxyl radicals which act as

• , olefins and others [1][2][3][14]. However, as POMs often only absorb light in the UV range, little is known about the visible-light photocatalytic activity of POMs [5][15]. One means of addressing this challenge is to tune the cluster structure and reactivity by incorporation of a reactive metal site into

• species H3[{Bi(dmso)3}4V13O40] × ca. 4 DMSO (= 1 × ca. 4 DMSO). 1 is formed spontaneously by reaction of Bi(NO3)3·5H2O and (n-Bu4N)3[H3V10O28] in dimethyl sulfoxide (DMSO) and it was shown that the cluster features both acidic and visible-light photocatalytic activity [29]. To date, to the best of our

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• up to nearly 80% and open circuit voltages up to the 1 V range [24]. Ho et al. revealed that the CdSe–TiO2 coupled system had a much higher photocatalytic activity than that of pure TiO2 and CdSe in the degradation of 4-chlorophenol under visible light irradiation [34]. Wang et al. reported facet ZnO

• water in TiO2 nanotubes with the addition of Au nanoparticles under 633 nm illumination, but a 4-fold reduction in the photocatalytic activity under UV radiation [66]. They ascribed the improvement of visible-light photocatalytic activity to the increase of the electron–hole pair generation rate by the

• used as an electron sink to improve the charge carrier separation and reduce the recombinations of electron–hole pairs. This way, the photocatalytic activity of the composite carbon nanotube/transition metal oxides is effectively improved (Figure 7a) [93]. Recently, it has been found that carbon

A visible-light-driven composite photocatalyst of TiO₂ nanotube arrays and graphene quantum dots

• Donald K. L. Chan,
• Po Ling Cheung and
• Jimmy C. Yu

Beilstein J. Nanotechnol. 2014, 5, 689–695, doi:10.3762/bjnano.5.81

• fabricated by covalently bonding GQDs onto amine-modified TNAs. The GQDs/TNAs composite retains the highly ordered nanotube morphology and well crystallized anatase phase. The high visible-light photocatalytic activity could be attributed to photosensitization of TNAs by GQDs. This research shows the

• ). Thermogravimetric analysis was performed in air using a thermogravimetric analyzer (Perkin Elmer, TGA 6). The samples were heated from 50 °C to 800 °C at a rate of 10 °C·min−1. Photocatalytic activity measurements: The photocatalytic activities of catalysts were evaluated by measuring the photodegradation of

Effects of the preparation method on the structure and the visible-light photocatalytic activity of Ag₂CrO₄

• Difa Xu,
• Shaowen Cao,
• Jinfeng Zhang,
• Bei Cheng and
• Jiaguo Yu

Beilstein J. Nanotechnol. 2014, 5, 658–666, doi:10.3762/bjnano.5.77

• 10.3762/bjnano.5.77 Abstract Silver chromate (Ag2CrO4) photocatalysts are prepared by microemulsion, precipitation, and hydrothermal methods, in order to investigate the effect of preparation methods on the structure and the visible-light photocatalytic activity. It is found that the photocatalytic

• activity of the prepared Ag2CrO4was highly dependent on the preparation methods. The sample prepared by microemulsion method exhibits the highest photocatalytic efficiency on the degradation of methylene blue (MB) under visible-light irradiation. The enhanced photocatalytic activity could be ascribed to

• ; photocatalytic activity; silver chromate; visible-light-driven; Introduction Semiconductor photocatalysis has been considered as a potential solution to the worldwide energy shortage and for counteracting environmental degradation [1][2][3][4][5]. Numerous efforts have been made to develop efficient and stable

Enhanced photocatalytic activity of Ag–ZnO hybrid plasmonic nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Vandana Choudhary,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2014, 5, 639–650, doi:10.3762/bjnano.5.75

• the synthesis of Ag–ZnO hybrid plasmonic nanostructures with enhanced photocatalytic activity by a facile wet-chemical method. The structural, optical, plasmonic and photocatalytic properties of the Ag–ZnO hybrid nanostructures were studied by X-ray diffraction (XRD), field emission scanning electron

• microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence (PL) and UV–visible absorption spectroscopy. The effects of citrate concentration and Ag nanoparticle loading on the photocatalytic activity of Ag–ZnO hybrid nanostructures towards sun-light driven degradation of methylene blue (MB

• physical and chemical stability, non-toxicity and low cost [11][12][13][14][15][16]. However, ZnO nanostructures suffer from drawbacks such as a high electron–hole recombination rate and the inefficient utilization of sun light, which limit their photocatalytic activity [17][18]. Several attempts have been

High activity of Ag-doped Cd_0.1Zn_0.9S photocatalyst prepared by the hydrothermal method for hydrogen production under visible-light irradiation

• Leny Yuliati,
• Melody Kimi and
• Mustaffa Shamsuddin

Beilstein J. Nanotechnol. 2014, 5, 587–595, doi:10.3762/bjnano.5.69

• activity of Cd0.1Zn0.9S was studied for the hydrogen production from water reduction under visible light irradiation. Results: Compared to the series prepared by the co-precipitation method, samples prepared by the hydrothermal method performed with a better photocatalytic activity. The sample with the

• . In addition to the larger absorption in the visible-light region, the increase in photocatalytic activity of samples with Ag doping may also come from the Ag species facilitating electron–hole separation. Conclusion: This study demonstrated that Ag doping is a promising way to enhance the activity of

• , the activity was not improved. After 5 h of reaction, Ag(0.03)-doped Cd0.1Zn0.9S and Ag(0.05)-doped Cd0.1Zn0.9S even showed a lower rate than that obtained from the undoped Cd0.1Zn0.9S. The enhancement in the photocatalytic activity of Ag(0.01)-doped Cd0.1Zn0.9S might be attributed to the better

Artificial sunlight and ultraviolet light induced photo-epoxidation of propylene over V-Ti/MCM-41 photocatalyst

• Van-Huy Nguyen,
• Shawn D. Lin,
• Jeffrey Chi-Sheng Wu and
• Hsunling Bai

Beilstein J. Nanotechnol. 2014, 5, 566–576, doi:10.3762/bjnano.5.67

• excitation of (Ti–O) moieties by UV irradiation but also to the indirect excitation through a charge transition from (V4+–OL−)* states as proposed in [34][35], which brings up a high photocatalytic activity [34]. Furthermore, Amano et al. reported that the lattice oxygen in the excited triplet state (V4+–OL

Mesoporous cerium oxide nanospheres for the visible-light driven photocatalytic degradation of dyes

• Subas K. Muduli,
• Songling Wang,
• Shi Chen,
• Chin Fan Ng,
• Cheng Hon Alfred Huan,
• Tze Chien Sum and
• Han Sen Soo

Beilstein J. Nanotechnol. 2014, 5, 517–523, doi:10.3762/bjnano.5.60

• , suggesting that the mechanism of photocatalytic activity under visible-light irradiation involves predominantly hydroxyl radicals as the active species. Keywords: cerium oxide; dye degradation; mesoporous; photocatalysis; visible light; Introduction The degradation of organic pollutants by affordable and

• . Control experiments were performed in the absence of scavengers (black line, Figure 5a). The established scavengers used include sodium oxalate for h+ (red), CrO3 for e− (green), isopropanol for •OH (blue), and 1,4-benzoquinone for •OOH/•O2− (grey, Figure 5a) [5]. The inhibition of photocatalytic activity

• of the material. The visible-light photocatalytic activity in the degradation of RhB surpasses that of the commercially available CeO2 and P25 TiO2 nanopowders. With a series of radical scavengers, the mechanism of the photocatalytic activity is proposed to involve a prominent role of •OH radicals as

Dye-sensitized Pt@TiO₂ core–shell nanostructures for the efficient photocatalytic generation of hydrogen

• Jun Fang,
• Lisha Yin,
• Shaowen Cao,
• Yusen Liao and
• Can Xue

Beilstein J. Nanotechnol. 2014, 5, 360–364, doi:10.3762/bjnano.5.41

• hydrothermal method. The dye-sensitization of these Pt@TiO2 core–shell structures allows for a high photocatalytic activity for the generation of hydrogen from proton reduction under visible-light irradiation. When the dyes and TiO2 were co-excited through the combination of two irradiation beams with

• recombination rate of photogenerated electrons and holes often leads to low quantum yields and a poor photocatalytic activity [6]. Tremendous efforts have been made to improve the photocatalytic performance of TiO2. One typical strategy is prolonging the lifetime of the electron–hole pair through deposition of

Preparation of NiS/ZnIn₂S₄ as a superior photocatalyst for hydrogen evolution under visible light irradiation

• Liang Wei,
• Yongjuan Chen,
• Jialin Zhao and
• Zhaohui Li

Beilstein J. Nanotechnol. 2013, 4, 949–955, doi:10.3762/bjnano.4.107

• be used as co-catalyst to enhance the photocatalytic hydrogen evolution over CdS [39]. It was found that NiS/CdS photocatalysts prepared via a simple hydrothermal loading method showed high photocatalytic activity for hydrogen evolution in the presence of lactic acid as sacrificial agent and a high

• evolution under visible light irradiation and the activity of NiS/ZnIn2S4 with optimized amount of NiS is even higher than that of Pt/ZnIn2S4. A possible enhancement mechanism based on the co-catalyst and the formed junction for the improved photocatalytic activity in the NiS/ZnIn2S4 system was also

• doping of only 0.2 wt % NiS onto ZnIn2S4 led to its highly enhanced photocatalytic activity for hydrogen evolution. The hydrogen evolution rate over 0.2 wt % NiS/ZnIn2S4 was enhanced to 70.5 μmol/h, about 5 times of that over pure ZnIn2S4 under similar condition. This indicates that NiS deposited on the

Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Neha Bhardwaj,
• Jaspal Singh,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2013, 4, 763–770, doi:10.3762/bjnano.4.87

• UV–vis absorption spectroscopy. SEM and TEM studies revealed flower-like structures consisting of nanosheets, formed due to oriented attachment of ZnO nanoparticles. Flower-like ZnO structures showed enhanced photocatalytic activity towards sun-light driven photodegradation of methylene blue dye (MB

• ] by the tape casting method. These ZnO plates showed a good photocatalytic activity for azo dyes that depended on their surface area. Shen et al. [34] have shown that depositing ZnO on silica nanoparticles is a simple and effective method to prepare photocatalysts that could degrade 90% methylene blue

• (MB) in 60 min. ZnO nanoparticles (NP) that were synthesized by wet chemical methods can be passivated by a Zn(OH)2 layer during ageing. Hong et al. [35] have shown that the photocatalytic activity of ZnO NP is drastically reduced when the is surface modified with polysterene. In this paper, we have

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

• Tanujjal Bora,
• Karthik K. Lakshman,
• Soumik Sarkar,
• Abhinandan Makhal,
• Samim Sardar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2013, 4, 714–725, doi:10.3762/bjnano.4.81

• ]. It has been reported that the native defects in the ZnO lattice, mostly the oxygen vacancy sites, play an important role in the photocatalytic activity of the nanostructures [11]. Oxygen vacancies have been reported as the cause of the characteristic green luminescence of ZnO [12][13][14]. These

• of surface defects. The rates of the photocatalytic degradation of BR were found to follow a first-order exponential equation with a maximum photocatalytic activity for the ZnO nanoparticles annealed at 250 °C. However, when the surface defects were reduced by annealing the ZnO nanoparticles at

• be attributed to the highest concentration of surface defect-states present in these nanoparticles. Under continuous UV irradiation, the ZnO nanoparticles annealed at 250 °C showed the maximum photocatalytic activity, which was almost 3.5 times higher than that of the as-synthesized ZnO nanoparticles

Photocatalytic antibacterial performance of TiO₂ and Ag-doped TiO₂ against S. aureus. P. aeruginosa and E. coli

• Kiran Gupta,
• R. P. Singh,
• Ashutosh Pandey and
• Anjana Pandey

Beilstein J. Nanotechnol. 2013, 4, 345–351, doi:10.3762/bjnano.4.40

• ., India Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad -211004. U.P., India. 10.3762/bjnano.4.40 Abstract This paper reports the structural and optical properties and comparative photocatalytic activity of TiO2 and Ag-doped TiO2 nanoparticles against different

• microorganisms including bacteria, fungi and viruses, because it has high photoreactivity, broad-spectrum antibiosis and chemical stability [1][2][3][4][5][6]. The photocatalytic activity of annealed TiO2 sturdily depends upon its existing phase, i.e., anatase, rutile, brokite. The anatase phase shows an

• is decreased. The photocatalytic activity of TiO2 nanoparticles depends not only on the properties of the TiO2 material itself, but also on the modification of TiO2 with metal or metal oxide. Previous studies reported that the addition of noble metal (silver and gold) in titanium dioxide enhances its

Paper modified with ZnO nanorods – antimicrobial studies

• Mayuree Jaisai,
• Sunandan Baruah and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2012, 3, 684–691, doi:10.3762/bjnano.3.78

• superoxide anions (·O2−), hydrogen peroxide (H2O2), hydroxyl radicals (·OH), hydrogendioxide anion (HO2−), and hydroperoxy radicals (·HO2). Surface area and surface defects play an important role in the photocatalytic activity of metal-oxide nanostructures. One-dimensional nanostructures such as nanorods

Mesoporous MgTa₂O₆ thin films with enhanced photocatalytic activity: On the interplay between crystallinity and mesostructure

• Jin-Ming Wu,
• Igor Djerdj,
• Till von Graberg and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2012, 3, 123–133, doi:10.3762/bjnano.3.13

• of the mesoporous films to assist the photodegradation of rhodamine B in water was studied. As a result, two maxima in the photocatalytic activity were identified in the calcination temperature range of 550–850 °C, peaking at 700 °C and 790 °C, and the origin of this was investigated by using

• achieved in order to optimize the physicochemical performance of mesoporous metal-oxide films. Keywords: magnesium tantalate; mesoporous materials; photocatalytic activity; self-assembly; thin films; Introduction Because of its excellent microwave dielectric properties, MgTa2O6 is one of the ternary

• photocatalytic activity is quite low. With the help of a block polymer P123, a Mg–Ta oxide powder with highly ordered mesopores was previously synthesized [11]. After removal of the P123 template by washing in water, the wormholelike microporous MgTa2O6 powder, though amorphous, showed enhanced water

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

Synthesis and catalytic applications of combined zeolitic/mesoporous materials

• Jarian Vernimmen,
• Vera Meynen and
• Pegie Cool

Beilstein J. Nanotechnol. 2011, 2, 785–801, doi:10.3762/bjnano.2.87

• properties and their photocatalytic activity in photodegradation processes [169], TiO2 formation often needs to be avoided in the synthesis of Ti-containing nanoporous siliceous materials since its presence can be detrimental for the catalytic activity associated with tetrahedrally coordinated Ti [170][171

Approaches to nanostructure control and functionalizations of polymer@silica hybrid nanograss generated by biomimetic silica mineralization on a self-assembled polyamine layer

• Jian-Jun Yuan and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2011, 2, 760–773, doi:10.3762/bjnano.2.84

• water contact angle could be attributed to the degradation of the low-surface-energy alkyl group due to the photocatalytic activity of anatase titania [47]. This was further confirmed by a simple control experiment. A superhydrophobic silica nanograss surface was produced by a similar DecTMS treatment

Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods

• Sunandan Baruah,
• Mohammad Abbas Mahmood,
• Myo Tay Zar Myint,
• Tanujjal Bora and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2010, 1, 14–20, doi:10.3762/bjnano.1.3

• Abstract Hydrothermally grown ZnO nanorods have inherent crystalline defects primarily due to oxygen vacancies that enhance optical absorption in the visible spectrum, opening up possibilities for visible light photocatalysis. Comparison of photocatalytic activity of ZnO nanorods and nanoparticle films on

• form of interstitials and vacancies, were intentionally created by faster growth of the nanorods by microwave activation. Visible light photocatalytic activity was observed to improve by ≈8% attributed to the availability of more electron deficient sites on the nanorod surfaces. Engineered defect

• surface defects play an important role in the photocatalytic activity of metal-oxide nanostructures, as the contaminant molecules need to be adsorbed on to the photocatalytic surface for the redox reactions to occur. The higher the effective surface area, the higher will be the adsorption of target