Large area continuous multilayer graphene membrane for water desalination

This manuscript reports the preparation of a large area (84 cm) desalination membrane based on multilayers (11 nm thickness) of B,N-codoped defective graphene. The process consists of coating a porous ceramic α-AlO support (100 nm pore size) with a continuous nanometric (50 nm) chitosan film containing adsorbed (NH)BO. Subsequent pyrolysis in the presence of hydrogen converts chitosan into multilayer defective B,N-codoped graphene. The partial removal of B and N dopant atoms by H during the pyrolysis causes the generation of subnanometric pores due to atom vacancy, as determined by control experiments in the absence of this gas. A NaCl and KCl removal efficiency from brackish water higher than 95% for a permeate flux of 24.3 L m h at 10 bars were achieved.This work was financially supported by: i) Project NOR-WATER funded by INTERREG VA Spain-Portugal cooperation programme, Cross-Border North Portugal/Galiza Spain Cooperation Program (POCTEP) and ii) Base Funding - UIDB/50020/2020 of the Associate Laboratory LSRE-LCM - funded by national funds through FCT/MCTES (PIDDAC). P.H. Presumido acknowledges FCT for his scholarship (SFRH/BD/138756/2018). V.J.P. Vilar acknowledges the FCT Individual Call to Scientific Employment Stimulus 2017 (CEECIND/01317/2017). Financial support by the Spanish Ministry of Science and Innovation (Severo Ochoa SEV2016 and RTI2018-890237-CO2-R1) and Generalitat Valenciana (Prometeo 2017-83) is also gratefully acknowledged

Turning carbon dioxide and ethane into ethanol by solar-driven heterogeneous photocatalysis over ruo2-and nio-co-doped srtio3

The current work focused on the sunlight-driven thermo-photocatalytic reduction of carbon dioxide (CO), the primary greenhouse gas, by ethane (C H), the second most abundant element in shale gas, aiming at the generation of ethanol (EtOH), a renewable fuel. To promote this process, a hybrid catalyst was prepared and properly characterized, comprising of strontium titanate (SrTiO) co-doped with ruthenium oxide (RuO) and nickel oxide (NiO). The photocatalytic activity towards EtOH production was assessed in batch-mode and at gas-phase, under the influence of different conditions: (i) dopant loading; (ii) temperature; (iii) optical radiation wavelength; (vi) consecutive uses; and (v) electron scavenger addition. From the results here obtained, it was found that: (i) the functionalization of the SrTiO with RuO and NiO allows the visible light harvest and narrows the band gap energy (ca. 14–20%); (ii) the selectivity towards EtOH depends on the presence of Ni and irradiation; (iii) the catalyst photoresponse is mainly due to the visible photons; (iv) the photocatalyst loses > 50% efficiency right after the 2nd use; (v) the reaction mechanism is based on the photogenerated electron-hole pair charge separation; and (vi) a maximum yield of 64 µmol EtOH g was obtained after 45-min (85 µmol EtOH g h) of simulated solar irradiation (1000 W m) at 200 C, using 0.4 g L of SrTiO:RuO:NiO (0.8 wt.% Ru) with [CO ]:[C H ] and [Ru]:[Ni] molar ratios of 1:3 and 1:1, respectively. Notwithstanding, despite its exploratory nature, this study offers an alternative route to solar fuels’ synthesis from the underutilized C H and CO.This work was financially supported by the Base Funding—UIDB/50020/2020 of the Associate Laboratory LSRE-LCM—funded by national funds through FCT/MCTES (PIDDAC). Larissa O. Paulista also wants to acknowledge for her doctoral fellowship (reference SFRH/BD/137639/2018), supported by FCT. Tânia F. C. V. Silva and Vítor J. P. Vilar acknowledge the FCT Individual Call to Scientific Employment Stimulus 2017 (CEECIND/01386/2017 and CEECIND/01317/2017, respectively). Josep Albero and Hermenegildo García are also grateful to the Spanish Ministry of Science and Innovation (RTI2018-098237-CO2-R1 and Severo Ochoa), Generalitat Valencia (Prometeo 2017/083) and European Union’s Horizon 2020 research and innovation programme under grant agreement No 862453, project FlowPhotochem, by financial contribution

Revalorisation of Posidonia Oceanica as Reinforcement in Polyethylene/Maleic Anhydride Grafted Polyethylene Composites

Posidonia Oceanica waste was used as reinforcement in a polyethylene matrix and the obtained composites were characterised by a tensile test and morphological analysis. The fi brous material derived from P. Oceanica wastes was characterised by morphological, thermal and chemical analysis, and a subsequent treatment with sodium hydroxide (NaOH) at different weight content (2, 5 and 10 wt%) was considered as an optimised method for surface modifi cation of pristine fi bres (PO). The TGA analysis and morphological investigation of the treated fi bres selected the 5 wt% of NaOH as the best treatment. Matrix compatibilisation with maleic anhydride grafted polyethylene was also considered and the effect on both grafting procedure and alkali treatment was studied for composites containing 20 wt% of fi bres. The results confi rmed that it is possible to aim for a revalorisation of coastal algae and seaweed wastes as raw material for polyolefi n matrix composites, even without applying a strong chemical treatment to the wast