Tin dioxide (SnO₂) used in various applications due to suitable band gap and tunable conductivity. It has excellent thermal, mechanical and chemical stability.

We designed a stable and efficient CuO based photocathode by tuning the crystallinity and surface morphology of films by rapid thermal treatment. The role of the annealing temperature on film crystallinity, optical absorption and grain size is studied. The impact of these parameters upon the photocatalytic water splitting performance of CuO films is investigated. We observed that a higher annealing temperature improves the film crystallinity and increases the grain size of CuO film, which significantly enhance the photocurrent generation capability. Rapid thermal annealing at 550 °C is found the best temperature to achieve the highest PEC performance. The thickness of the CuO photocathodes is also optimized and we observed that 550 nm thick films results in the highest photocurrent of 1.68 mA cm⁻². Our optimized CuO photocathode has shown better stability against photo-corrosion and a 30% decrease in the initial value of photocurrent is measured after 15 min, while a 60% decrease in the photocurrent is noticed in case of the as-deposited film.

Multilayer coating structure comprising a copper (Cu) layer sandwiched between titanium dioxide (TiO₂) were demonstrated as a transparent heat reflecting (THR) coating on glass for energy-saving window application. The main highlight is the utilization of Cu, a low-cost material, in-lieu of silver which is widely used in current commercial heat reflecting coating on glass. Color tunable transparent heat reflecting coating was realized through the design of multilayer structure and process optimization. The impact of thermal treatment on the overall performance of sputter deposited TiO₂/Cu/TiO₂ multilayer thin film on glass substrate is investigated in detail. Significant enhancement of transmittance in the visible range and reflectance in the infra-red (IR) region has been observed after thermal treatment of TiO₂/Cu/TiO₂ multilayer thin film at 500 °C due to the improvement of crystal quality of TiO₂. Highest visible transmittance of 90% and IR reflectance of 85% at a wavelength of 1200 nm are demonstrated for the TiO₂/Cu/TiO₂ multilayer thin film after annealing at 500 °C. Performance of TiO₂/Cu/TiO₂ heat reflector coating decreases after thermal treatment at 600 °C. The wear performance of the TiO₂/Cu/TiO₂ multilayer structure has been evaluated through scratch hardness test. The present work shows promising characteristics of Cu-based THR coating for energy-saving building industry.

Global plastic waste is increasing rapidly. In general, densely populated regions generate tons of plastic waste daily, which is sometimes disposed of on land or diverged to sea. Most of the plastics created in the form of waste have complex degradation behavior and are non-biodegradable by nature. These remain intact in the environment for a long time span and potentially originate complications within terrestrial and marine life ecosystems. The strategic management of plastic waste and recycling can preserve environmental species and associated costs. The key contribution in this work focuses on ongoing efforts to utilize plastic waste by introducing blockchain during plastic waste recycling. It is proposed that the efficiency of plastic recycling can be improved enormously by using the blockchain phenomenon. Automation for the segregation and collection of plastic waste can effectively establish a globally recognizable tool using blockchain-based applications. Collection and sorting of plastic recycling are feasible by keeping track of plastic with unique codes or digital badges throughout the supply chain. This approach can support a collaborative digital consortium for efficient plastic waste management, which can bring together multiple stakeholders, plastic manufacturers, government entities, retailers, suppliers, waste collectors, and recyclers.