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Manganese-doped calcium aluminate powder was prepared at furnace temperatures as low as 500°C using the combustion route without further calcining treatment. Powder X-ray diffraction, thermogravimetric analysis and scanning electron microscopy measurements were used to characterize the as-prepared combustion products, while the optical properties were studied using photoluminescence. Photoluminescence studies of Mn doped CaAl₂O₄ showed green emission from Mn²⁺ ions. EPR investigations also indicated the presence of Mn²⁺ ions in the prepared material.

For the first of its kind, Cr${}^{3+}$-substituted calcium hexaferrite (CaCr_xFe${}_{12-x}$O${}_{19}$ ($x=1$, 3, 5 and 7)) nanoparticles (NPs) were synthesized via a facile, economical, eco-friendly lemon juice extract mediated green solution combustion method. The samples were calcined followed by characterization. The Bragg reflections confirm the formation of a single phase M-type hexaferrite crystal structure. No other impurity or mixed phases are observed even after the substitution of Cr${}^{3+}$ to the host matrix. Meanwhile, the crystallite size decreases from 29.44 to 19.92nm with an increase in the substitution of Cr${}^{3+}$ ions. The surface morphological analysis shows the presence of agglomerated irregularly shaped NPs. The direct energy band gap estimated using Wood and Tauc’s relation depicts the decrease in energy band gap from 2.98 to 2.74eV with an increase in the substitution of Cr${}^{3+}$ ions. These Cr${}^{3+}$-substituted calcium hexaferrite NPs were predicted to be useful in high-frequency applications based on structural, dielectric, and magnetic studies.

This work investigated combustion performance of the premixed and diffusion burners by measuring flame temperature and gas emissions with used lubricating oil (ULO) and used cooking oil (UCO). Air–fuel ratio (AFR) is an important parameter to investigate combustion performance. Flame temperatures and gas emissions of the burners were examined to know the combustion behavior. The results found were that the flame temperatures in the premixed burner were higher than the diffusion burner at all the AFRs. The maximum flame temperature was obtained at AFR = 16 at all types of burners and fuel blending ratios. The highest flame temperature was $1340^{\circ }\mathrm{\text{C}}$, which occurred when using 100% ULO with premixed burner at AFR = 16. By adding UCO into ULO, the flame temperatures can be decreased. The premixed burner produced 86.67% and 71.23% less CO and HC emissions, respectively, than the diffusion burner, in contrast, the premixed burner formed 26.31% and 54.7% higher ${\mathrm{\text{CO}}}_2$ and ${\mathrm{\text{NO}}}_x$ emissions, respectively, than the diffusion burner.

We have successfully synthesized ZnO nanoparticles (NPs) from solution combustion method using combustible fuel (Green gram). XRD pattern confirms that the prepared compound is composed of wurtzite hexagonal zinc-oxide. FTIR spectrum of ZnO NPs shows the band at ~ 417 cm^-1 associated with the characteristic vibration of Zn-O. The UV-Vis spectrum shows a strong absorption band at ~ 365 nm which is blue shifted due to quantum confinement effect. TEM images show the average sizes of the nanoparticles are found to be almost ~ 15–30 nm. The as-synthesized product shows good electrochemical sensing of dopamine. Furthermore the antibacterial properties of ZnO NPs were investigated by their bactericidal activity against four bacterial strains using the agar well diffusion method.

In the present work, Zinc Oxide nanoparticles (ZnO Nps) have been prepared by a simple and low temperature solution combustion method using Zinc nitrate as a precursor and solid water melon juice as a novel fuel for the first time. The structure and morphology of the synthesized ZnO NPs have been analyzed using various analytical techniques such as Powder X-ray diffraction, FTIR spectroscopy, Raman spectroscopy, UV-Visible spectroscopy, photoluminescence spectroscopy, scanning electron microscope and transmission electron microscope. ZnO NPs show good photo catalytic activity for the degradation of methylene blue (MB) dye. It also shows significant antibacterial activities against three bacterial strains.

In this paper, we have successfully synthesized ZnO nanoparticles (Nps) via solution combustion method using sugarcane juice as the novel fuel. The structure and morphology of the synthesized ZnO Nps have been analyzed using various analytical tools. The synthesized ZnO Nps exhibit excellent photocatalytic activity for the degradation of methylene blue dye, indicating that the ZnO Nps are potential photocatalytic semiconductor materials. The synthesized ZnO Nps also show good electrochemical sensing of dopamine. ZnO Nps exhibit significant bactericidal activity against Klebsiella aerogenes, Pseudomonas aeruginosa, Eschesichia coli and Staphylococcus aureus using agar well diffusion method. Furthermore, the ZnO Nps show good antioxidant activity by potentially scavenging 1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The above studies clearly demonstrate versatile applications of ZnO synthesized by simple eco-friendly route.

NiFe₂O₄-reduced graphene oxide (RGO) hybrid materials (NFRGs) were synthesized by a simple one-step combustion method. The structures, morphologies and magnetic properties were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and vibrating sample magnetometer analysis. The results show that graphene oxide sheets are not oxidized, but reduced to RGO. The superparamagnetic behavior of NFRGs was observed. The as-synthesized magnetically separable NFRGs show improved photodegradation performance when compared to neat NiFe₂O₄, attributed to the narrowing band gap, the efficient transfer of photo-generated electron from NiFe₂O₄ to RGO sheets, and the improved adsorptive property of photocatalyst due to the high specific surface area of RGO sheets.

Some people think that carbon and sustainable development are not compatible. This textbook shows that carbon dioxide (CO₂) from the air and bio-carbon from biomass are our best allies in the energy transition, towards greater sustainability. We pose the problem of the decarbonation (or decarbonization) of our economy by looking at ways to reduce our dependence on fossil carbon (coal, petroleum, natural gas, bitumen, carbonaceous shales, lignite, peat). The urgent goal is to curb the exponential increase in the concentration of carbon dioxide in the atmosphere and hydrosphere (Figures 1.1 and 1.2) that is directly related to our consumption of fossil carbon for our energy and materials The goal of the Paris agreement (United Nations COP 21, Dec. 12, 2015) of limiting the temperature increase to 1.5 degrees (compared to the pre-industrial era, before 1800) is becoming increasingly unattainable (Intergovermental Panel on Climate Change (IPCC), report of Aug. 6, 2021). On Aug. 9, 2021 Boris Johnson, prime minister of the United Kingdom, declared that coal needs to be consigned to history to limit global warming. CO₂ has an important social cost…

Natural gas consists mainly of methane (CH₄) and ethane (CH₃CH₃) and other hydrocarbons in small quantities. Depending on the source it may also contain CO₂, nitrogen (N₂), hydrogen sulfide (H₂S) and helium (He). It is very abundant and its combustion contributes to the increase of the CO₂ content in the biosphere. Natural gas is a non-renewable fuel (Section 5.1). It is widely used to produce electricity, heat, chemicals including hydrogen, and hydrocarbons (liquid fuels) and as a fuel for motor vehicles…