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Optimising the photoelectrochemical performance of hematite photoanodes for solar water splitting requires better understanding of the relationships between dopant distribution, structural defects and photoelectrochemical properties. Here, we use complementary characterisation techniques including electron microscopy, conductive atomic force microscopy (CAFM), Rutherford backscattering spectroscopy (RBS), atom probe tomography (APT) and intensity modulated photocurrent spectroscopy (IMPS) to study this correlation in Ti-doped (1 cat.%) hematite films deposited by pulsed laser deposition (PLD) on F:SnO2 (FTO) coated glass substrates. The deposition was carried out at 300 ��C, followed by annealing at 500 deg C for 2 h. Upon annealing, Ti was observed by APT to segregate to the hematite/FTO interface and into some hematite grains. Since no other pronounced changes in microstructure and chemical composition were observed by electron microscopy and RBS after annealing, the non-uniform Ti redistribution seems to be the reason for a reduced interfacial recombination in the annealed films, as observed by IMPS. This results in a lower onset potential, higher photocurrent and larger fill factor with respect to the as-deposited state. This work provides atomic-scale insights into the microscopic inhomogeneity in Ti-doped hematite thin films and the role of defect segregation in their electrical and photoelectrochemical properties.

Urban population growth has permanently increased the commodity demands and freight flow within urban areas. The retail/postal industry is intent on finding appropriate internal approaches and a new business model to respond to the adverse impacts generated by urban freight activities. Usage of emerging transport modes is an efficient solution for these industries. Nevertheless, considerable research has paid less attention to the implementation status of distribution innovations, as well as to their suitability and application restrictions. Concurrently, a comprehensive consideration of various distribution innovations that operate together as a system is lacking. To this end, this paper adopted a literature review method and GE multifactorial analysis. Specifically, this paper reviewed the related articles that were published in the past six years (2013–2018) to define the concept of distribution innovations. In addition, we adopted the approach of GE multifactorial analysis to analyze the application status of distribution innovations from the perspective of academic research and company implementation. Following the suitability assessment and application of restriction analysis, we proposed the concept of sustainable inner-urban intermodal transport (SIUIT) for the retail/postal industry. This paper contributes to the sustainable urban freight literature by exploring possible future research directions of SIUIT.

Voluntary environmental management programs for firms have become an increasingly popular instrument of environmental policy. However, the literature’s conclusion on the effectiveness of suchprograms is ambiguous, and for the European region there is a lack of evidence based on a large control group. We seek to fill this gap with an evaluation of the Eco-Management and Audit Scheme (EMAS), introduced in 1995 by the European Union as a premium certification of continuous pro-environmental efforts above regulatory minimum standards. It is more demanding than other voluntary programsdue to annual public reports of the environmental performance and targets for improvements. We use official firm-level production census data on the German manufacturing sector, a major energy consumer and emitter in Europe. To account for the self-selection of firms, we combine the Coarsened Exact Matching approach with a Difference-in-Differences estimation. Our results do not suggest reductions of firms’ CO2 intensity and energy intensity neither before nor after certification. Moreover, program participants do not increase renewable energy consumption or investments into the protection of the environment and climate. Our results are robust to a variety of checks and call into question the effectiveness of the EMAS program concerning these particular outcome variables.

Abstract Over a period of more than 10 years, fundamental research on frost formation and defrosting behaviour of lamel type air coolers has been pursued at the Delft University of Technology. Many experiments have been performed to support the Dutch Standard for testing air coolers, NEN 1876. This standard gives an objective description of the performance of air coolers under frosting conditions. For the system designer it is very important to judge the average cooling performance and coefficient of performance during the total cycle, consisting of cooling period and defrosting period. For this purpose two dimensionless numbers were derived, which also make it possible to determine, by using computer models, the optimum cooling period before defrosting starts. Finally the use of the developed theories for cost optimization of refrigerating plants and the latest experiences with the Dutch Standard for air coolers, NEN 1876, are discussed.

Abstract In many cases, hazardous wastes are subject to thermal treatment at elevated temperatures. Some types of wastes do not have a sufficient calorific value to cover the heat demand of the high temperature process. For thermal treatment of e.g. filter residues, dusts, sulfuric acid, aluminium dross, foundry sand, or waste water, supplementary energy supply is needed. The specific energy demand ranges from 0.5 to 2.5 kWh/kg (2–10 MJ/kg). An important aim of process optimisation is the reduction of (fossil) energy consumption and exhaust gas flow. Concentrated solar energy promises advantages when applied to high energy consuming waste treatment processes with regard to substitute fossil or electric energy consumption, to reduce CO2 emissions, and exhaust gas flow. In parallel to conceptional studies, a solar-heated rotary kiln mini-plant has been designed and constructed for tests in the DLR solar furnace. The tests will give indications of boundary conditions for solar thermal treatment or conversion of selected hazardous materials.

Abstract The kinetics of methane hydrate decomposition was studied using a semibatch stirred-tank reactor. The decomposition was accomplished by reducing the pressure on a hydrate slurry in water to a value below the three-phase equilibrium pressure at the reactor temperature. The data were obtained at temperatures from 274 to 283 K and pressures from 0.17 to 6.97 MPa. The stirring rates were high enough to eliminate mass-transfer effects. Analysis of the data indicated that the decomposition rate was proportional to the particle surface area and to the difference in the fugacity of methane at the equilibrium pressure and the decomposition pressure. The proportionality constant showed an Arrhenius temperature dependence. An estimate of the hydrate particle diameters in the experiments permitted the development of an intrinsic model for the kinetics of hydrate decomposition.

Abstract Hybrid TiO2/SiO2 thin films deposited by material printing technique on flexible substrates were prepared, characterized and tested for solar photocatalytic disinfection. Effect of surface hydrophilicity/hydrophobicity of printed coatings on photocatalytic disinfection was studied by means of (i) drinking water contaminated with natural consortia of fecal bacteria (gram-negative: Escherichia coli and total coliforms; gram-positive: Enterococci), and (ii) seawater containing pathogenic gram-negative bacteria (Vibrio owensii, Vibrio alfacsensis and Vibrio harveyi). Inactivation of gram-negative bacteria in drinking water with fecal contamination by solar photocatalysis was slightly more efficient than solar disinfection, while for gram-positive bacteria similar efficiency was observed. These results, in combination with observed release of titanium from coatings (detected by means of inductively coupled plasma atomic emission spectrometer), indicate that TiO2/SiO2 needs further improvements for solar photocatalytic disinfection of drinking water. Efficiency of seawater disinfection towards gram-negative Vibrio spp. (Vibrio owensii, Vibrio alfacsensis and Vibrio harveyi) was significantly enhanced when TiO2/SiO2 coatings were used under natural solar light. Moreover, hydrophobic thin films led to faster Vibrio spp. inactivation as compared to hydrophilic ones, which was attributed to higher bacteria adhesion on hydrophobic coatings. However, decrease of photocatalytic activity of hydrophobic TiO2/SiO2 coatings was observed after ten experimental cycles mainly due to deposition of salts on the surface of photocatalyst. Generally, results of this study suggest that autochthonous bacteria such as Vibrio spp. in seawater are significantly more resistant to solar disinfection in comparison with not autochthonous bacteria such as Escherichia coli, total coliforms and Enterococci in contaminated drinking water.