Metal-free catalysis based on nitrogen-doped carbon nanomaterials: a photoelectron spectroscopy point of view

• Mattia Scardamaglia and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2018, 9, 2015–2031, doi:10.3762/bjnano.9.191

• have addressed in the last decades are described, in particular the enduring debate on the role of the different nitrogen functionalities in the catalytic activity of nitrogen-doped carbon nanotubes and graphene. Keywords: catalysis; carbon nanotubes; graphene; metal-free; nitrogen doping

• absorption of H2 on the catalyst lowering the cell performance [6]. In parallel, the research on the catalytic activity of low-cost and metal-free catalysts has proceeded for decades. The discovery of catalytic properties of carbon alloys with nitrogen dates back to 1926 when Rideal and Wright reported their

• discovery of their catalytic performance in the ORR: beginning with nitrogen-doped carbon fibres (2006 [18]), followed by carbon nanotubes (2009 [19]) and finally graphene (2010 [20]). In 2006, Matter and Ozkan reported on a metal-free ORR catalyst containing nitrogen-doped carbon fibers. The authors

Perovskite-structured CaTiO₃ coupled with g-C₃N₄ as a heterojunction photocatalyst for organic pollutant degradation

• Ashish Kumar,
• Christian Schuerings,
• Suneel Kumar,
• Ajay Kumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2018, 9, 671–685, doi:10.3762/bjnano.9.62

• 2D–2D nanocomposites could effectively improve the specific surface area and provide abundant reaction sites to adsorb reactant species on their surface, which can significantly enhance the photocatalytic activity [15][16]. Recently, graphitic carbon nitride (g-C3N4), which is a metal-free polymeric

Mechanistic insights into plasmonic photocatalysts in utilizing visible light

• Kah Hon Leong,
• Azrina Abd Aziz,
• Lan Ching Sim,
• Pichiah Saravanan,
• Min Jang and
• Detlef Bahnemann

Beilstein J. Nanotechnol. 2018, 9, 628–648, doi:10.3762/bjnano.9.59

• . Such materials have already been applied in various environmental and energy conversion applications [36]. Recently, the evolution of a metal-free semiconductor, graphitic carbon nitride (g-C3N4), has been discovered as an alternative for plasmonic photocatalysts. This metal-free semiconductor by

Engineering of oriented carbon nanotubes in composite materials

• Razieh Beigmoradi,
• Abdolreza Samimi and
• Davod Mohebbi-Kalhori

Beilstein J. Nanotechnol. 2018, 9, 415–435, doi:10.3762/bjnano.9.41

• oxides for metal-free catalysis [15] or in synergy with metal oxides [16][17], especially for sustainable energy applications [18][19]. Because of their electronic properties, CNT composites offer unmatched opportunities for conductive tissue regeneration [20], particularly if alignment, and thus 3D

Towards molecular spintronics

• Georgeta Salvan and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2017, 8, 2464–2466, doi:10.3762/bjnano.8.245

• considered molecules spans from heterotrinuclear bis(oxamato)-type and bis(oxamidato)-type complexes [1][2][3], to exchange-coupled dinickel complexes [4], metallo-phthalocyanines [5][6][7], metallo-porphyrins [8][9] and charge-transfer complexes [10][11], to metal-free molecules like pentacene-derivatives

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• building structural units (Figure 3a,b) [63]. g-C3N4 was first reported by Wang et al. in 2009 as an interesting, metal free, n-type semiconductor, polymeric photocatalytic material for the water splitting reaction to evolve H2 and O2 [64]. The unique optical, electrical and physiochemical properties of g

• transfer. Moreover, in nanometer-sized MoS2, exposed S atoms have strong affinity to H+ ions in solution, which are reduced to H2 by transferred electrons from the CB of CdS. Similarly, a noble-metal-free, ternary nanocomposite of TiO2–MoS2–graphene has been reported by Yu et al. for H2 generation [126

Formation of ferromagnetic molecular thin films from blends by annealing

• Peter Robaschik,
• Ye Ma,
• Salahud Din and
• Sandrine Heutz

Beilstein J. Nanotechnol. 2017, 8, 1469–1475, doi:10.3762/bjnano.8.146

• , respectively [17][20], assuming that MnPc is isostructural with CuPc. This represents an intermediate case with a partial transformation from α- to β-phase as shown earlier for metal-free phthalocyanine thin films where Yim et al. proposed a phase-transition mechanism that involves tilting of the α-phase

Growth, structure and stability of sputter-deposited MoS₂ thin films

• Reinhard Kaindl,
• Bernhard C. Bayer,
• Roland Resel,
• Thomas Müller,
• Viera Skakalova,
• Gerlinde Habler,
• Rainer Abart,
• Alexey S. Cherevan,
• Dominik Eder,
• Maxime Blatter,
• Fabian Fischer,
• Jannik C. Meyer,
• Dmitry K. Polyushkin and
• Wolfgang Waldhauser

Beilstein J. Nanotechnol. 2017, 8, 1115–1126, doi:10.3762/bjnano.8.113

• noble metal-free catalytic material for the hydrogen evolution reaction (HER) in electrochemical water splitting, which is fundamental to a hydrogen-based energy economy [14]. Density function theory showed the feasibility of MoS2 supported on graphite to catalyse electrochemical hydrogen evolution at a

Performance of natural-dye-sensitized solar cells by ZnO nanorod and nanowall enhanced photoelectrodes

• Saif Saadaoui,
• Mohamed Aziz Ben Youssef,
• Moufida Ben Karoui,
• Rached Gharbi,
• Emanuele Smecca,
• Vincenzina Strano,
• Salvo Mirabella,
• Alessandra Alberti and
• Rosaria A. Puglisi

Beilstein J. Nanotechnol. 2017, 8, 287–295, doi:10.3762/bjnano.8.31

• metal-free organic dye with high performance [8][11][12][13]. Indeed, several studies were carried out using natural dyes, such as spinach and red turnip as a sensitizer. However, their efficiency is lower than that of commercial organometallic dyes. In this work, we investigate two different natural

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

• Jakub S. Prauzner-Bechcicki,
• Lukasz Zajac,
• Piotr Olszowski,
• Res Jöhr,
• Antoine Hinaut,
• Thilo Glatzel,
• Bartosz Such,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

• occupied by a metal atom, e.g., Cu, Co, and Fe, giving rise to CuPc, CoPc, and FePc molecules, respectively. It is possible that, instead of a metal atom in the void, two hydrogen atoms may exist bonded to the nitrogen of the pyrrole group; this is referred to as a metal-free phthalocyanine (H2Pc

• )[44], FePc/TiO2(110) [45], and metal-free Pc/TiO2(110) [47] systems. Let us first take a look at the results published for a CuPc/TiO2 system. For CuPc overlayers that were a few nanometres thick on TiO2(110), a decrease in the work function values was reported [27]. Wang, Ye and Wu studied the

• first layer, resulting in the alteration of the electronic structure and charge transfer from the molecules, is a significant disadvantage [45]. The results obtained for metal-free phthalocyanines are in line with those mentioned above. Molecules in the first layer adsorb in a flat-lying geometry and

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• obtained by using metal masks with suitable patterning. However, if the generation of holes through the reducing reaction (Equation 13) is faster than the silicon oxidation/etching reaction, holes generated at the silicon–metal interface can diffuse toward confining, metal-free, regions [127]. Thus

• , silicon can become partially etched in neighbouring regions around the metal features [117][124][128] (Figure 14). This limits the minimum distances between metal patterns, as for example the nanowire pitch. Furthermore, hole diffusion in metal-free regions gives porous vertical structures. Porous

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

• platinum was demonstrated to be more efficient than metallic platinum as cocatalyst for hydrogen production [23][24]. Taking into account the cost of the designed photocatalyst for commercial purposes, the development of noble-metal free cocatalysts is still valued. Alternative cocatalysts such as MoS2

• the overall photocatalytic activity. Our work demonstrates that efficient and low cost photocatalytic hydrogen production can be achieved through the substitution of noble metal cocatalyst with a properly engineered surface heterojunction [29]. In addition to the screening for a noble-metal free

• junction of Ga2O3 [71]. The improved photocatalytic activity results from the efficient charge separation and transfer across the α–β phase junctions of the Ga2O3 particles. We have found that spherical twin-containing noble-metal-free Cd0.5Zn0.5S is a superb photocatalyst for hydrogen production, showing

Resonance of graphene nanoribbons doped with nitrogen and boron: a molecular dynamics study

• Ye Wei,
• Haifei Zhan,
• Kang Xia,
• Wendong Zhang,
• Shengbo Sang and
• Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 717–725, doi:10.3762/bjnano.5.84

• the electronic and quantum transport properties of graphene. Such doped graphene is envisioned with exciting applications as high-performance FET devices [8], and metal-free electrocatalyst for oxygen reduction fuel cells [9]. In addition to doping, various graphene derivatives have also been

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

• . reported a layer-by-layer self-assembly between positively charged CdS quantum dots and negatively charged exfoliated titanate nanosheets to design noble-metal free photocatalysts. The resultant composites exhibited a much higher photocatalytic H2 production activity than pristine titanate and CdS quantum

Neutral and charged boron-doped fullerenes for CO₂ adsorption

• Suchitra W. de Silva,
• Aijun Du,
• Wijitha Senadeera and
• Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 413–418, doi:10.3762/bjnano.5.49

• years metal organic frameworks (MOFs) have emerged as solid CO2 adsorbent materials due to their tuneable chemical and physical properties. Particularly, there is growing interest for metal free carbon-based nanomaterials for gas adsorption. Carbon-based nanomaterials such as fullerene, carbon nanotubes

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

• loading amount of 0.5 wt %. This work demonstrates a high potential of the developing of environmental friendly, cheap noble-metal-free co-catalyst for semiconductor-based photocatalytic hydrogen evolution. Keywords: co-catalyst; hydrogen evolution; NiS; photocatalytic; photocatalysis; visible light

• ][10][11], oxynitrides [12][13][14], as well as the metal-free semiconductors [15] have already been developed. Among the numerous types of semiconductor systems studied, metal sulfides have demonstrated promising activities towards hydrogen evolution from water containing sacrificial reagents under

Parallel- and serial-contact electrochemical metallization of monolayer nanopatterns: A versatile synthetic tool en route to bottom-up assembly of electric nanocircuits

• Jonathan Berson,
• Assaf Zeira,
• Rivka Maoz and
• Jacob Sagiv

Beilstein J. Nanotechnol. 2012, 3, 134–143, doi:10.3762/bjnano.3.14

• the mechanical force pressing the two surfaces together and the time of contact. Metal-free and metal-covered OTSeo sites such as those displayed in Figure 2, Figure 3, and Figure 5 (see below) can be unambiguously identified in lateral-force (contact-mode) and semicontact-mode (tapping) topographic

• nanodots (OTSeo@OTS/Si); (middle row) array of metal/monolayer template nanodots (Ag/OTSeo@OTS/Si); (bottom row) recovered array of OTSeo@OTS/Si monolayer-template nanodots, after removal of the deposited metal. Contact-mode topographic images of the metal-free dots (top and bottom rows) show a similar

• , implemented by moving the positively biased tip (mobile anode) across the OTSeo lines that play the role of cathode for metal deposition (see text); (right) resulting pattern-within-pattern array of silver/monolayer nanodots (Ag/OTSeo@OTSeo@OTS/Si denotes Ag/OTSeo sites within metal-free OTSeo regions located