Abstract: A method for producing a chromium nitride (CrN) thin film is provided. The method includes reactive radio frequency magnetron sputtering chromium onto a substrate in the presence of a gaseous mixture including nitrogen and argon to form the CrN thin film, where a ratio of the nitrogen gas to the argon gas is 1:2 to 1:10, and where the CrN thin film has an average thickness of 500 to 1500 nm. The CrN film as prepared by the method of the present disclosure can be used in sensors for cryogenic temperature.

Abstract: A droplet-impingement, flow-assisted electro-Fenton (DFEF) catalyst, system, and method can degrade to trace level organic materials, such as ?-blockers in water. A silica/carbon-x % iron composite (RHS/C-x % Fe) can be made, e.g., from rice husks and iron ions into heterogeneous catalysts of varied iron content. The DFEF approach can improve oxygen saturation, mass transfer of ?-blockers at the cathode, and continuous electrogeneration of hydroxyl radicals (.OH) in solution and at boron-doped anode surfaces. A central composite design (CCD) can reduce costs and increase efficiency. Beta-blockers can be completely degraded within 15 minutes, following pseudo first-order kinetics with rate constants of 0.19 to 2.72×10?2 (acebutolol) and 0.16 to 2.54×10?2 (propranolol) at increasing catalyst concentration. Beta-blocker degradation can be mostly by .OHbulk rather than .OHadsorbed for anodic oxidation (AO) at BDD electrode. The degradation efficiency of ?-blockers can be: DFEF>FEF>BEF>AO.