As the most commonly-used renewable energy in the world energy consumption, the potential and popularity of biomass energy is significantly underestimated. In the United States in 2018, renewable energy accounted for 11% of the national energy consumption, with 44.5% contributed by biomass energy. This article will focus on one feedstock, bio-waste and residue, in biomass resources. Furthermore, this journal will include an overview of the history of the technique, explanation of the fundamental physical principles, along with the discussions regarding major technology implementation of the conversion technique, and finally end with an evaluation of the environmental impacts and economic opportunities and challenges. At the end of the journal, we will show that the development of bio-waste and residue conversion techniques will naturally benefit from biomass’ carbon cycle and the variety of techniques available. Moreover, it has a large potential no matter environmentally or economically, along with technological advancement and the development of government regulations to minimize its harm.

Even today, the problem of greenhouse gas emissions and recycling endanger human health continuously. The dynamic structure of the flexible MOFs (metal-organic frameworks) allows them to change their structure in response to external stimuli. And a fresh approach to reducing greenhouse gas emissions comes from using flexible frames for gas absorption, notably in the area of lower energy and highly selective gas separation. This review starting from the design and improvement of flexible MOFs summarizes some excellent cases in carbon dioxide capture. Finally, the potential applications of flexible MOFs are classified and briefly analyzed.

The impact of water sources on humans has many facets. Our daily consumption is only a small part of the water that is used to irrigate plants, raise fish and fowl, and so on. The environment we live in and the survival of the organisms around us all depend on the safety of the water source. Water sources need to adhere to strict standards for pathogens, oxygen, salt, heat, heavy metals, and more. Otherwise, unclean water sources can cause disease and even be fatal. Since covid-19 broke out in 2019, it has had many impacts on people's lives, and it is no different for water treatment. The original treatment of water sources needs to be protected and improved to ensure the safety of the water. This article will analyze and list the original water treatment process, the impact of covid-19, and some of the current solutions.

TiO2 thin film has become a widely used photocatalyst due to its stable chemical properties, suitable edge position, non-toxicity and low cost, and the film structure is conducive to recycling and loading. However, because the band gap of titanium dioxide is relatively wide, visible light is difficult to be utilized, which also limit the utilization of TiO2. In recent years, non-metallic doping has been proven to be an extraordinarily efficient methodologies to reduce band gap and improve photocatalytic efficiency of TiO2 films. In this paper, the basic principle of photocatalysis and the principle of reducing band gap by doping inorganic non-metallic elements are briefly introduced, and the preparation methods of N, C and B inorganic non-metallic elements doped TiO2 films are reviewed, as well as their functions on reducing band gap of TiO2. Finally, the research status of inorganic non-metallic element doped TiO2 thin film in photodecomposition of water and organic decomposition in catalytic solution was introduced.