Maohong Fan

Recently, carbon dioxide capture and conversion, along with hydrogen from renewable resources, provide an alternative approach to synthesis of useful fuels and chemicals. People are increasingly interested in developing innovative carbon dioxide hydrogenation catalysts, and the pace of progress in this area is accelerating. Accordingly, this perspective presents current state of the art and outlook in synthesis of light olefins, dimethyl ether, liquid fuels, and alcohols through two leading hydrogenation mechanisms: methanol reaction and Fischer-Tropsch based carbon dioxide hydrogenation. The future research directions for developing new heterogeneous catalysts with transformational technologies, including 3D printing and artificial intelligence, are provided.

This review summarizes the recent progress in the design, fabrication, and application of visible light-responsive photocatalysts.

It is generally accepted by the scientific community that anthropogenic CO2 emissions are leading to global climate change, notably an increase in global temperatures commonly referred to as global warming. The primary source of anthropogenic CO2 emissions is the combustion of fossil fuels for energy. As society's demand for energy increases and more CO2 is produced, it becomes imperative to decrease the amount emitted to the atmosphere. One promising approach to do this is to capture CO2 at the effluent of the combustion site, namely, power plants, in a process called postcombustion CO2 capture. Technologies to achieve this are heavily researched due in large part to the intuitive nature of removing CO2 from the stack gas and the ease in retrofitting existing CO2 sources with these technologies. As such, several reviews have been written on postcombustion CO2 capture. However, it is a fast-developing field, and the most recent review papers already do not include the state-of-the-art research. Notable among CO2 capture technologies are amine-based technologies. Amines are well-known for their reversible reactions with CO2, which make them ideal for the separation of CO2 from many CO2-containing gases, including flue gas. For this reason, this review will cover amine-based technology developed and published in and after the year 2013.

This research was designed for the first time to investigate the activities of photocatalytic composite, Ag3PO4/g-C3N4, in converting CO2 to fuels under simulated sunlight irradiation. The composite was synthesized using a simple in situ deposition method and characterized by various techniques including Brunauer-Emmett-Teller method (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and an electrochemical method. Thorough investigation indicated that the composite consisted of Ag3PO4, Ag, and g-C3N4. The introduction of Ag3PO4 on g-C3N4 promoted its light absorption performance. However, more significant was the formation of heterojunction structure between Ag3PO4 and g-C3N4, which efficiently promoted the separation of electron-hole pairs by a Z-scheme mechanism and ultimately enhanced the photocatalytic CO2 reduction performance of the Ag3PO4/g-C3N4. The optimal Ag3PO4/g-C3N4 photocatalyst showed a CO2 conversion rate of 57.5 μmol · h(-1) · gcat(-1), which was 6.1 and 10.4 times higher than those of g-C3N4 and P25, respectively, under simulated sunlight irradiation. The work found a new application of the photocatalyst, Ag3PO4/g-C3N4, in simultaneous environmental protection and energy production.