34 documents found, page 1 of 4
Catalyst-free CNTs growth on red mud-based alkali activated adsorbents: Innovat...
Carvalheiras, João; Oliveira, Inês E.; Silva, Ricardo M.; Silva, Rui F.; Novais, Rui M.; Labrincha, João A.The synthesis and growth of carbon nanotubes (CNTs) on red mud containing alkali activated materials (AAMs) envisioned for wastewater treatment applications is reported for the first time. This novel avenue takes advantage of the iron present in the red mud (RM), a massively produced industrial waste, promoting the growth of CNTs and avoiding the need for commercial catalysts. X-ray diffraction shows that upon ...
A state-of-the-art review of recent advances in porous geopolymer: applications...
Ettahiri, Youssef; Bouargane, Brahim; Fritah, Kamal; Akhsassi, Brahim; Pérez-Villarejo, L.; Aziz, Ayoub; Bouna, Lahcen; Benlhachemi, AbdeljalilThis review article discusses the potential of porous geopolymers as a promising approach for the removal of various contaminants, including heavy metals, dyes, drug residues, pharmaceuticals, and pesticides from aqueous solutions. Additionally, this review provides an overview of the recent preparation methods of geopolymers and their characteristics. The high porosity of the geopolymers allows for the adsorpt...
High performance cork-templated ceria for solar thermochemical hydrogen product...
Oliveira, Fernando Almeida Costa; Barreiros, M. Alexandra; Haeussler, Anita; Caetano, Ana P. F.; Mouquinho, Ana; Silva, P. Oliveira e; Novais, Rui M.ABSTRACT: Water splitting by solar energy-driven two-step thermochemical cycles is a promising approach for large-scale production of renewable fuels (e.g. hydrogen). The key challenge is developing materials capable of withstanding the harsh environmental conditions and to ensure high reliability in use, particularly in terms of redox kinetics and better activity at low operation temperatures. In this work, we...
Solar redox cycling of ceria structures based on fiber boards, foams, and biomi...
Haeussler, Anita; Abanades, Stéphane; Oliveira, Fernando Almeida Costa; Barreiros, M. Alexandra; Caetano, Ana P. F.; Novais, Rui M.; Pullar, Robert C.ABSTRACT: Solar thermochemical conversion of H2O and captured CO2 is considered for the production of high-value solar fuels and CO2 valorization, using nonstoichiometric oxygen-exchange redox materials. This work aims to compare the thermochemical cycle performance of different ceria structures, including biomimetic cork-templated ceria (CTCe), ceria foams (CeF), and ceria bulk fiber boards (CeFB), to study th...
Geopolymer foams: an overview of recent advancements
Novais, Rui M.; Pullar, Robert.C.; Labrincha, João A.Geopolymer foams (highly porous materials) have emerged as one of the most exciting materials over the past few years due to their remarkable properties, low cost and green synthesis protocol, enabling their use in various high added-value applications. Review papers on porous geopolymers are uncommon, and the emphasis has been given to materials processing and properties, while the applications were only brief...
Synthesis of red mud derived M-type barium hexaferrites with tuneable coercivity
Carvalheiras, João; Novais, Rui M.; Mohseni, Farzin; Amaral, João S.; Seabra, Maria P.; Labrincha, João A.; Pullar, Robert C.Hexagonal ferrites can be employed in a multitude of applications, the most common hexaferrites are the M ferrites such as BaFe12O19 (barium hexaferrite, BaM). It is known that if Fe3+ is substituted with a combination of Ti4+/Co2+ the coercivity of BaM can be reduced to produce soft M ferrites with easily switchable magnetisation. They can be utilised as powders, films or bulk ceramics, and can be manufactured...
Red mud-based inorganic polymer spheres: innovative and environmentally friendl...
Gameiro, Tânia; Novais, Rui M.; Correia, Catarina L.; Carvalheiras, João; Seabra, Maria P.; Labrincha, João A.; Duarte, Armando C.; Capela, IsabelRed mud-based inorganic polymer spheres were used as alternative pH regulators and process enhancers in sequencing batch anaerobic reactors treating cheese whey. This byproduct tends to quickly acidify under anaerobic conditions, and the common route to control pH and ensure suitable conditions for methane production involves the use of commercial alkaline raw materials. The spheres were synthesized using signi...
A review of solar thermochemical CO2 splitting using ceria-based ceramics with ...
Pullar, Robert C.; Novais, Rui M.; Caetano, Ana P. F.; Barreiros, M. Alexandra; Abanades, Stéphane; Oliveira, Fernando Almeida CostaABSTRACT: This review explores the advances in the synthesis of ceria materials with specific morphologies or porous macro- and microstructures for the solar-driven production of carbon monoxide (CO) from carbon dioxide (CO2). As the demand for renewable energy and fuels continues to grow, there is a great deal of interest in solar thermochemical fuel production (STFP), with the use of concentrated solar light ...
A review of solar thermochemical CO2 splitting using ceria-based ceramics with ...
Pullar, Robert C.; Novais, Rui M.; Caetano, Ana P. F.; Barreiros, M. Alexandra; Abanades, Stéphane; Oliveira, Fernando Almeida CostaABSTRACT: This review explores the advances in the synthesis of ceria materials with specific morphologies or porous macro- and microstructures for the solar-driven production of carbon monoxide (CO) from carbon dioxide (CO2). As the demand for renewable energy and fuels continues to grow, there is a great deal of interest in solar thermochemical fuel production (STFP), with the use of concentrated solar light ...
A sustainable multi-function biomorphic material for pollution remediation or U...
Quarta, Alessandra; Novais, Rui M.; Bettini, Simona; Iafisco, Michele; Pullar, Robert C.; Piccirillo, ClaraFor the first time, highly porous ZnO-based biomorphic materials were synthesised using cork as a natural sustainable template. In the first step, waste cork powder was pyrolysed and converted into inorganic carbon. This template was then infiltrated using a novel approach employing an aerosol of zinc-containing solutions. The infiltrated powders were calcined to convert the precursors into zinc oxide. Dependin...