Nathan Skillen

• BSc (Hons), PhD
• Lecturer and Programme Director at Queen's University Belfast

Research in the field of photocatalytic reactors in the past three decades has been an area of extensive and diverse activity with an extensive range of suspended and fixed film photocatalyst configurations being reported. The key considerations for photocatalytic reactors, however, remain the same; effective mass transfer of pollutants to the phot...

a b s t r a c t This paper describes a novel doped titania immobilised thin film multi tubular photoreactor which has been developed for use with liquid, vapour or gas phase media. In designing photocatalytic reactors mea-suring active surface area of photocatalyst within the unit is one of the critical design parameters. This dictate greatly limit...

The use of photocatalysis for the photosplitting of water to generate hydrogen and oxygen has gained interest as a method for the conversion and storage of solar energy. The application of photocatalysis through catalyst engineering, mechanistic studies and photoreactor development has highlighted the potential of this technology, with the number o...

With advancements in the development of visible light responsive catalysts for H2 production frequently being reported, photocatalytic water splitting has become an attractive method as a potential 'solar fuel generator'. The development of novel photo reactors which can enhance the potential of such catalyst, however, is rarely reported. This is p...

As a globally abundant source of biomass, lignocellulosic biomass has been the centre of attention as a potential resource for green energy generation and value‐added chemical production. A key component of lignocellulosic biomass, lignin, which is comprised of aromatic monomers, is a potential feedstock for value added chemical production. The cle...

Cellulose is is made up of linear polymers of glucose monomers that could be a crucial source for valuable chemicals and sustainable liquid fuels. Cellulose is however, very stable and its conversion to a useful fuel or platform chemical products remains a significant challenge [3,4]. Photocatalysis is a versatile technology which has demonstrated...

Bioenergy is widely included in energy strategies for its GHG mitigation potential. Bioenergy technologies will likely have to be deployed at scale to meet decarbonisation targets, and consequently biomass will have to be increasingly grown / mobilised. Sustainability risks associated with bioenergy may intensify with increasing deployment and wher...

The application of photocatalysis for the disinfection of water has been extensively reported over the past 30 years. Titanium dioxide (TiO 2) has been the most widely and successfully used photocatalyst to date; however, it is not without its limitations. Frequently observed long lag times, sometimes up to 60 min, before bacterial inactivation beg...

Glucose is a key intermediate in cellulose photoreforming for H2 production. This work presents a mechanistic investigation of glucose photoreforming over TiO2 and Pt/m-TiO2 catalysts. Analysis of the intermediates formed in the process confirmed the α-scission mechanism of glucose oxidation forming arabinose (Cn-1 sugar) and formic acid in the ini...

Many recent research studies have reported indirect methods for the detection and quantification of OH radicals generated during photocatalysis. The short lifespan and high reactivity of these radicals make indirect detection using probes such as coumarin a more viable quantification method. Hydroxyl radical production is commonly monitored using f...

This study introduces for the first time an electroanalytical investigation and novel voltammetric method for the determination of emamectin benzoate (EB) using a cathodically pretreated boron-doped diamond electrode (CTP-BDDE). The CPT-BDDE electrode exhibited a well-defined irreversible signal at ∼1.35 V (vs. Ag/AgCl) using cyclic voltammetry. Di...

As a consequence of the issues resulting from global climate change many nations are starting to transition to being low or net zero carbon economies. To achieve this objective practical alternative fuels are urgently required and hydrogen gas is deemed one of the most desirable substitute fuels to traditional hydrocarbons. A significant challenge,...

Cyanobacteria and their toxic secondary metabolites present challenges for water treatment globally. In this study we have assessed TiO2 immobilized onto recycled foamed glass beads by a facile calcination method, combined in treatment units with 365 nm UV-LEDs. The treatment system was deployed in mesocosms within a eutrophic Brazilian drinking wa...

Photocatalytic reforming of biomass has emerged as an area of significant interest within the last decade. The number of papers published in the literature has been steadily increasing with keywords such as ‘hydrogen’ and ‘visible’ becoming prominent research topics. There are likely two primary drivers behind this, the first of which is that bioma...

The valorization of biomass via photocatalysis is an area of expanding research with advances in new technologies and materials with a view toward enhanced sustainability being reported. A significant challenge within this field, however, is understanding the impact photocatalysis has on more recalcitrant compounds present in biomass, such as ligni...

As the need for improved methods to convert biomass into value-added compounds increases, so too does the requirement for complementary rapid in situ monitoring methods. In this study, for the first time, an in situ electroanalytical method for monitoring the production of 2,5-diformylfuran from the photocatalytic oxidation of 5-hydroxymethylfurfur...

Hydrogen peroxide (H2O2) is an important chemical as it is an environmentally friendly oxidant for organic synthesis and environmental remediation as well as a promising candidate for the liquid fuel. Photocatalytic generation of H2O2 is sustainable, and many efforts have been put into the development of new catalysts to gain high H2O2 yields. In t...

Phthalates are widely used plasticizers, but have endocrine-disrupting effects, which cause harm to both humans and the wider environment. Photocatalytic technologies have been shown to be promising methods for removal of a range of environmental pollutants in water. In this paper the photocatalytic oxidation of Diisobutyl phthalate (DiBP) using tw...

The valorisation of lignin has gained significant interest in bioenergy, which is driven by the abundance of the material coupled with the potential to form value-added compounds. As a result, the range of technologies deployed for this application has increased and more recently includes advanced oxidation processes such as photocatalysis. The com...

Renewable energy, especially biofuels, has the potential to supplement a part of the existing fossil-based transportation fuels. Biofuels such as bioethanol can be produced from established glucose fermentation processes; however, cheap and efficient glucose production is a hindering factor. Cellulose, the world’s most abundant organic material, is...

Photocatalytic remediation technology has been shown to be a favorable approach for the removal of a range of environmental pollutants in water treatment. While this approach can often achieve complete degradation, often overlooked are reaction intermediates that are potentially as harmful as the original parent compound. In the case of photocataly...

The development, and demonstration of efficiencies, of photocatalytic technologies are often dependent on the method by which activity is measured. The screening of both materials and reactors is a key aspect in the development process and both are critical in determining whether the technology is suitable for a required application. Given this, de...

Abstrac While phthalate esters are commonly used as plasticizers to improve the flexibility and workability of polymeric materials, their presence and detection in various environments has become a significant concern. Phthalate esters are known to have endocrine-disrupting effects, which affects reproductive health and physical development. As a r...

BACKGROUND With an increase in global bioenergy production, the ‘biorefinery concept’ has now become a significant focus of research. The desire to achieve efficient conversion of biomass material into both energy and value‐added products requires a combination of technologies and processes. As such, the photocatalytic reforming of feedstocks such...

The multifunctional potential of a catalyst previously synthesised for thermal processes is explored by investigating its activity for photocatalytic production of H2 from glycerol, a by-product from the manufacture of bio-diesel. The studied catalyst contains TiO2 doped with Al2O3 that was derived from aluminum foil waste. This catalyst showed hig...

In recent years, significant attention has been given to the development of photoelectrochemical materials capable of producing high current densities under illumination for a range of applications. Titanium dioxide nanotubes (TiNTs) have emerged as a favourable nanomaterial due to a reduced rate of recombination coupled with the ability to generat...

Blooms of blue-green algae (cyanobacteria) in water reservoirs frequently produce highly toxic secondary metabolites including microcystins which have resulted in both human and animal fatalities. To tackle this global problem, we present here a viable solution: utilising the photo-catalytic power of TiO2 immobilised on glass beads that are encased...

➢ The conversion of sustainable feedstocks to both energy and high value products, while minimising harmful emissions, is the ultimate objective in renewable energy research. ➢ Photocatalytic technology has shown potential as a low cost environmentally friendly approach to achieve this objective, especially with a view towards cellulose reforming....

Efficient energy production and waste valorisation are the most challenging fields in photocatalysis. Photocatalytic H2 production, specifically in the past have utilised a variety of sacrificial electron donors (SEDs) as feedstocks. Cellulose I (native micro crystalline cellulose) being the world’s most abundant organic material has previously bee...

Building easy-to-handle bulk materials with nanoproperties is crucial for many nanotechnology-based real-world applications. Here, we describe a simple one-pot method based on nanoparticle self-assembly of pickering emulsions and in situ polymer deposition for preparing particles consisting of a rigid micro-polymer core covered in exposed surface l...

Recently, photocatalytic reactors have been designed with a view towards overcoming mass transfer limitations especially in systems with immobilised catalysts. This paper reports the design of a titanium “bladed” propeller with TiO2 immobilised on the blades. To evaluate the propeller efficiency, modelling using COMSOL Multiphysics® was validated e...

The rapid and efficient removal of pollutants from water is of vital importance. The removal of such compounds is often achieved by adsorption techniques, however the deployment of advanced oxidation processes can present a method for complete degradation. 2-Methyl-4-chlorophenoxyacetic acid (MCPA) has been shown to be present in high concentration...

The design of photocatalytic reactors for use in bacterial disinfection studies is often based on defined laboratory conditions, which are not a true representation of the harsh and ever-changing environment that bacteria encounter in nature. In this study four parameters (growth phase, biofilm production, pH and irradiation source) subject to cont...

The development of photocatalytic technology has grown significantly since its initial report and as such, a number of screening methods have been developed to assess activity. In the field of environmental remediation, a crucial factor is the formation of highly oxidising species such as OH radicals. These radicals are often the primary driving fo...

Alternative renewable energy must emerge to sustainably meet the energy demands of the present and future. Current alternatives to fossil fuels are electricity from solar, wind and tidal energies and biofuels. Biofuels, especially bioethanol could be produced from lignocellulosic feedstock via pre-treatment and fermentation. The cellulose I content...

A simple method for determining hydroxyl radical yields on semiconductor photocatalysts is highly desirable, especially when comparing different photocatalyst materials. This paper reports the screening of a selection of visible light active photocatalysts such as Pt-C3N4, 5% LaCr doped SrTiO3, Sr0.95Cr0.05TiO3 and Yellow TiO2 and compares them aga...

Photosynthesis is a natural mechanism which is capable of not only converting solar energy to a potential food stock but also reducing atmospheric CO2 levels. The process of artificial photosynthesis attempts to mimic this mechanism through the development of materials and technology that can harvest solar energy for high energy conversion to renew...