Plants have been used for multiple purposes over thousands of years in various applications such as traditional Chinese medicine and Ayurveda. More recently, the special properties of phytochemicals within plant extracts have spurred researchers to pursue interdisciplinary studies uniting nanotechnology and biotechnology. Plant-mediated green synthesis of nanomaterials utilises the phytochemicals in plant extracts to produce nanomaterials. Previous publications have demonstrated that diverse types of nanomaterials can be produced from extracts of numerous plant components. This review aims to cover in detail the use of plant extracts to produce copper (Cu)-based nanomaterials, along with their robust applications. The working principles of plant-mediated Cu-based nanomaterials in biomedical and environmental applications are also addressed. In addition, it discusses potential biotechnological solutions and new applications and research directions concerning plant-mediated Cu-based nanomaterials that are yet to be discovered so as to realise the full potential of the plant-mediated green synthesis of nanomaterials in industrial-scale production and wider applications. This review provides readers with comprehensive information, guidance, and future research directions concerning: (1) plant extraction, (2) plant-mediated synthesis of Cu-based nanomaterials, (3) the applications of plant-mediated Cu-based nanomaterials in biomedical and environmental remediation, and (4) future research directions in this area.

Food packaging plays an important role in maintaining the quality of packaged food from any chemical, physical and environmental damage. Conventionally, plastic material is used in the food industry because of its large availability and excellent mechanical performance at low cost. However, the usage of plastic packaging in huge amounts creates environmental and health issues. The preparation methods of the biodegradable packaging or films have been reviewed. The properties of the packaging are varied depending on the ingredients of the films. The mechanical properties such as tensile strength of the biodegradable films can be improved by additive cellulose fibre or metal oxide composition. Metal oxide composition is added to the production of the film as reinforcement. The increase in metal oxide composition indicates the tendency to increase tensile strength. However, a decrease in elongation at break is observed as the percentage of modified cellulose increases. The addition of a natural bioactive compound such as antioxidant, antimicrobial and water vapour permeability also enhance the functionality of the film and provides intelligent communication with the consumer. The review provided information for readers to choose a suitable preparation method for biodegradable films. The article also offers data on materials selection based on the comparison of the film properties. Biodegradable packaging approach to mitigate the management of plastic waste which serves as an urgent crisis recently and supports in moving towards a sustainable environment.

Aviation is a highly energy-intensive sector, making it the second-biggest source of greenhouse gas emissions in the transportation sector, with road transport leading the way. Emissions continue to rise despite advancements in aircraft efficiency over the past six decades due to the increasing demand for air travel. Reviewing the reduction of carbon emissions in aviation is essential to protect the environment, drive innovation and secure a sustainable future in aviation. Stakeholders responsible for reducing carbon emissions are primarily found in the industrial sector. The challenges and opportunities related to reducing carbon emissions in aviation are investigated with a focus on Sustainable Aviation Fuels (SAF), advancements in fuel-efficient aircraft, and improvements in air traffic management. Studies have shown that using SAF, derived from renewable resources such as waste oils, algae, and municipal waste, can reduce lifecycle carbon emissions by up to 80% compared to conventional jet fuel. The use of SAF is limited due to cost and the difficulty in producing it. In addition, the use of electric and hydrogen-powered aircraft is highlighted, as it can revolutionise the industry by offering zero-emission alternatives for both short- and long-haul flights. Recommendations are provided to achieve net-zero emissions by 2050, aligning with the Sustainable Development Goals (SDGs) set by the United Nations, specifically SDG 11 (Sustainable Cities and Communities) and SDG 13 (Climate Action).

The liquid waste produced due to palm oil processing is called palm oil mill effluent (POME). It is challenging to manage because of its high production and inadequate treatment. The discharge of raw POME into the environment will result in multiple detrimental effects and environmental pollution. This short review compares the conventional treatment methods in Malaysia, which are the ponding system for the treatment of POME and the open or closed digesting tank. These systems are unable to achieve the standards set by the Department of Environment (DOE) of Malaysia. Photocatalysts, which are well-known as catalysts in the decomposition of organic contaminants, are suggested as an alternative method for POME treatment. The viability of using photocatalytic technology to remediate POME waste is discussed in this short review. The advancement and improvement of the nanoparticle system for POME treatment are identified based on past studies. It is aimed at providing readers with a clear comparison of conventional POME treatment methods and information on photocatalysis as an alternative POME treatment method.

The agricultural residues that are not well-managed will cause environmental deterioration. In fact, they can be used as alternative sources for production and application in various industries due to their attractive properties such as absorption ability, mechanical properties and biodegradability. In recent advancements, agricultural residues are broadly used to form nanocellulose. In this study, nanocellulose was extracted from plant leaves of coconut (Cocos nucifera), sugarcane (Saccharum officinarum L.) and lemongrass (Cymbopogon) which are abundant agricultural waste. Chemical pre-treatment was carried out by boiling dried leaves at 80°C in NaOH. The extraction was conducted under homogenous conditions using high pressure homogenization with speed at 1000 rpm for 30 mins to produce nanocellulose. The samples were characterized for surface morphology, UV-Vis spectrum, Fourier transmission using FTIR and water absorption. The properties displayed by the formed nanocellulose were analysed and compared for further recommendation. These materials have a high potential to be used in different fields towards a sustainable future.