Abstract: A surface-enhanced Raman scattering (SERS) substrate and its method of formation is disclosed. The surface-enhanced Raman scattering (SERS) substrate comprises a solid support, a first noble metal nanoparticles is disposed on the solid support, a porous oxide layer comprising transition metal oxide nanoparticles is disposed on the first noble metal nanoparticles and a second noble metal nanoparticles is disposed on the porous oxide layer. The porous oxide layer prevents contact between the first noble metal nanoparticles and the second noble metal nanoparticles and has a mean pore size of 2 to 30 nm.

Abstract: A surface-enhanced Raman scattering (SERS) substrate and its method of formation is disclosed. The surface-enhanced Raman scattering (SERS) substrate comprises a solid support, a first noble metal nanoparticles is disposed on the solid support, a porous oxide layer comprising transition metal oxide nanoparticles is disposed on the first noble metal nanoparticles and a second noble metal nanoparticles is disposed on the porous oxide layer. The porous oxide layer prevents contact between the first noble metal nanoparticles and the second noble metal nanoparticles and has a mean pore size of 2 to 30 nm.

Abstract: A method of forming an alkali metal-doped calcium-SiAlON material is provided. The method includes mixing calcium-SiAlON powder and an alkali metal hydroxide to form a reaction mixture. The mixture further includes spark plasma sintering (SPS) the reaction mixture at 800 to 940 degrees Celsius (° C.) to form the alkali metal-doped calcium-SiAlON material. The alkali metal hydroxide is present in an amount of 0.1 to 10 weight percentage (wt. %), based on a total weight of the reaction mixture.

Abstract: A surface-enhanced Raman scattering (SERS) substrate and its method of formation is disclosed. The surface-enhanced Raman scattering (SERS) substrate comprises a solid support, a first noble metal nanoparticles is disposed on the solid support, a porous oxide layer comprising transition metal oxide nanoparticles is disposed on the first noble metal nanoparticles and a second noble metal nanoparticles is disposed on the porous oxide layer. The porous oxide layer prevents contact between the first noble metal nanoparticles and the second noble metal nanoparticles and has a mean pore size of 2 to 30 nm.

Abstract: A method of preparing porous nitrogen-doped carbon nanosheets by pyrolysis of Albizia procera leaves. The nitrogen-doped carbon nanosheets display enhanced electrochemical properties including large surface area and specific capacitance. Electrodes coated with the nitrogen-doped carbon nanosheets are particularly suitable for use in supercapacitors and solar cells.

Abstract: A room temperature nitrogen dioxide gas sensor comprising tin(IV) oxide decorated with gold nanoparticles is described. The tin(IV) oxide may have an average layer thickness of 10-1,000 nm, and is topped with dispersed gold nanoparticles having an average longest dimension of 200-650 nm. The room temperature nitrogen dioxide gas sensor may be used to detect and measure levels of nitrogen dioxide gas at room temperature and at concentrations of 100 ppb-1800 ppm, with a high stability. A method of making the room temperature nitrogen dioxide sensor is also described, and involves sputtering to deposit a tin(IV) oxide layer and a gold layer on a substrate, followed by annealing.

Abstract: A method of preparing porous nitrogen-doped carbon nanosheets by pyrolysis of Albizia procera leaves. The nitrogen-doped carbon nanosheets display enhanced electrochemical properties including large surface area and specific capacitance. Electrodes coated with the nitrogen-doped carbon nanosheets are particularly suitable for use in supercapacitors and solar cells.

Abstract: A room temperature nitrogen dioxide gas sensor comprising tin(IV) oxide decorated with gold nanoparticles is described. The tin(IV) oxide may have an average layer thickness of 10-1,000 nm, and is topped with dispersed gold nanoparticles having an average longest dimension of 200-650 nm. The room temperature nitrogen dioxide gas sensor may be used to detect and measure levels of nitrogen dioxide gas at room temperature and at concentrations of 100 ppb-1800 ppm, with a high stability. A method of making the room temperature nitrogen dioxide sensor is also described, and involves sputtering to deposit a tin(IV) oxide layer and a gold layer on a substrate, followed by annealing.

Abstract: A room temperature hydrogen gas sensor comprising tin(IV) oxide and platinum layered on an electrode substrate is described. The tin(IV) oxide may be polycrystalline with an average layer thickness of 10-700 nm, and topped with platinum having an average layer thickness of 1-15 nm. The room temperature hydrogen gas sensor may be used to detect and measure levels of H2 gas at room temperature and at concentrations of 50-1800 ppm, with fast response and high stability. A method of making the room temperature hydrogen gas sensor is also described, and involves sputtering to deposit tin(IV) oxide and platinum on a substrate, which is then subjected to low-temperature annealing step.