Carbon emissions in China's steel industry from a life cycle perspective: Carbon footprint insights.

China is the most important steel producer in the world, and its steel industry is one of the most carbon-intensive industries in China. Consequently, research on carbon emissions from the steel industry is crucial for China to achieve carbon neutrality and meet its sustainable global development goals. We constructed a carbon dioxide (CO2) emission model for China's iron and steel industry from a life cycle perspective, conducted an empirical analysis based on data from 2019, and calculated the CO2 emissions of the industry throughout its life cycle. Key emission reduction factors were identified using sensitivity analysis. The results demonstrated that the CO2 emission intensity of the steel industry was 2.33 ton CO2/ton, and the production and manufacturing stages were the main sources of CO2 emissions, accounting for 89.84% of the total steel life-cycle emissions. Notably, fossil fuel combustion had the highest sensitivity to steel CO2 emissions, with a sensitivity coefficient of 0.68, reducing the amount of fossil fuel combustion by 20% and carbon emissions by 13.60%. The sensitivities of power structure optimization and scrap consumption were similar, while that of the transportation structure adjustment was the lowest, with a sensitivity coefficient of less than 0.1. Given the current strategic goals of peak carbon and carbon neutrality, it is in the best interest of the Chinese government to actively promote energy-saving and low-carbon technologies, increase the ratio of scrap steel to steelmaking, and build a new power system.

Application of new tetra-cationic imidazolium ionic liquids for capture and conversion of CO2 to amphiphilic calcium carbonate nanoparticles as a green additive in water based drilling fluids.

Conversion and capture of carbon pollutants based on carbon dioxide to valuable green oil-field chemicals are target all over the world for controlling the global warming. The present article used new room temperature amphiphilic imidazolium ionic liquids with superior surface activity in the aqueous solutions to convert carbon dioxide gas to superior amphiphilic calcium carbonate nanoparticles. In this respect, tetra-cationic ionic liquids 2-(4-dodecyldimethylamino) phenyl)-1,3-bis (3-dodecyldimethylammnonio) propyl) bromide-1-H-imidazol-3-ium acetate and 2-(4-hexyldimethylamino) phenyl)-1,3-bis(3-hexcyldimethylammnonio) propyl) bromide-1 H-imidazol-3-ium acetate were prepared. Their chemical structures, thermal as well as their carbon dioxide absorption/ desorption characteristics were evaluated. They were used as solvent and capping agent to synthesize calcium carbonate nanoparticles with controlled crystalline lattice, sizes, thermal properties and spherical surface morphologies. The prepared calcium carbonate nanoparticles were used as additives for the commercial water based drilling mud to improve their filter lose and rheology. The data confirm that the lower concentrations of 2-(4-dodecyldimethylamino) phenyl)-1,3-bis (3-dodecyldimethylammnonio) propyl) bromide-1-H-imidazol-3-ium acetate achieved lower seawater filter lose and improved viscosities.

Let the dust settle: Impact of enhanced rock weathering on soil biological, physical, and geochemical fertility.

Terrestrial enhanced rock weathering (ERW) is a promising carbon dioxide removal technology that consists in applying ground silicate rock such as basalt on agricultural soils. On top of carbon sequestration, ERW has the potential to raise the soil pH and release nutrients, thereby improving soil fertility. Despite these possible co-benefits, concerns such as heavy metal pollution or soil structure damage have also been raised. To our knowledge, these contrasted potential effects of ERW on soil fertility have not yet been simultaneously investigated. This field trial aimed at assessing the impact of ERW on biological, physical, and chemical soil properties in a temperate agricultural context. To do so, three vineyard fields in Switzerland were selected for their distinct geochemical properties and were amended with basaltic rock powder at a dose of 20 tons per hectare (2 kg.m-2). On each field, basaltic rock powder was either applied one year before the sampling campaign, one month before the sampling campaign, or not applied (control) for a total of 27 plots with 9 repetitions of each level. Overall, basaltic rock powder addition had a predominantly positive to neutral effect on soil fertility. Most soil properties showed no significant change either 1 month or 1 year post application. Nevertheless, our study highlighted a significant increase in earthworm abundance (+71 % on average), soil respiration (+50 %) and extractable sodium concentration (+23 %) as early as 1 month post application. The higher soil respiration raises the question of CO2 losses from organic matter mineralization that could limit ERW's efficiency. The increase in sodium raises concerns about a sodification risk potentially damaging soil fertility. These elements now require further investigation before enhanced rock weathering can be considered a viable and secure carbon dioxide removal technology.

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO.

An efficient one-step synthesis of diarylacetic acids was successfully performed by electrochemical direct carboxylation of diarylmethanol compounds in DMSO. Constant-current electrolysis of diarylmethanol species in DMSO using a one-compartment cell equipped with a Pt cathode and a Mg anode in the presence of carbon dioxide induced reductive C(sp3)-O bond cleavage at the benzylic position in diarylmethanol compounds and subsequent fixation of carbon dioxide to produce diarylacetic acids in good yield. This protocol provides a novel and simple approach to diarylacetic acids from diarylmethanol species and carbon dioxide without transformation of the hydroxy group into appropriate leaving groups, such as halides and esters including carbonates.

Visible-Light-Promoted Reduction of Nitroarenes with Formate Salts as Reductants.

A visible-light-promoted reduction of nitrobenzenes using formate salts as the reductant was developed. A wide range of nitrobenzenes can be converted into aniline products in a transition metal free fashion. Mechanistic studies revealed that radical species (carbon dioxide radical anion and thiol radical) are key intermediates for the transformation. We anticipate that this method will provide a valuable and green strategy for the reduction of nitrobenzenes.

Synergies quantification and evolution on air pollutant and CO2 emissions driven by different socio-economic effects.

Realizing a synergistic reduction of air pollutant and CO2 emissions (APCE) is an important approach to promote a green socio-economic transformation in China, and it can provide a solid foundation for the achievement of clean energy production and climate action under a sustainable development goal framework. The objective of this study is to explore the quantitative relationship and evolution of synergies between APCE in industrial sectors driven by different socio-economic effects from 2007 to 2020 in China. The results indicated that the main sectors of pollutant emissions had consistency, however, large differences in the reduction efficiency of emissions exist among pollutants. The efficiency in reducing CO2 emissions was about 48% lower when compared with reductions of SO2 (95%), NOx (86%), and smoke and dust (83%) emissions from 2007 to 2020. The effects of improved technology were the main contributor to a reduction in pollutant emissions, but the synergies between APCE driving by it were not achieved. While the synergies between APCE driven by structure and final demand effects were significant. The synergies between NOx and CO2 emissions were stronger driven by final demand structure and type effects, with correlation coefficients of 1.06 and 1.13, respectively. Besides, the degree of synergistic reduction between APCE in most industrial sectors was around zero. Therefore, the efficiency of synergistic pollution reduction should be improved with the development of a synergistic governance system for industrial sectors. The structural decomposition analysis based on input-output model combined with the cross-elasticity analysis method to quantitively synergies between APCE from the consumption (demand) perspective, considering the connections between industrial sectors with socio-economic developing, which would contribute to the industrial synergistic reduction and green transformation as the consumption driven gradually increasing.

Different preferences for inorganic carbon influence CO2 flux under Cyanobacteria or Chlorophyta dominance days.

Algae play critical roles in the carbon dioxide (CO2) exchange between the water bodies and the atmosphere. However, the effects of prokaryotic and eukaryotic algae on carbon utilization, CO2 flux, and the underlying mechanisms remain poorly understood. Therefore, this study investigated the differences in carbon preferences and CO2 fluxes under different algal dominance days. Our research revealed that dissolved inorganic carbon (DIC) concentration fluctuations had a limited effect on the relative abundance of algae. However, shifts in dominant algal phyla induced changes in DIC, with Cyanobacteria preferring HCO3- and Chlorophyta preferring CO2. Analysis of the water chemistry balance indicated that the growth of Chlorophyta had a 15.59 times greater effect on CO2 sinks compared with that of Cyanobacteria. During the Cyanobacteria dominance days, the lower DIC concentration did not result in a reduction in CO2 emissions. However, increases in the dissolved organic carbon concentration provided a favorable environment for Cyanobacteria, which promoted CO2 emissions. The CCM model indicated that the growth of Chlorophyta resulted in CO2 uptake rates at least 3.57 times higher and CO2 leakage rates up to 0.97 times lower compared to Cyanobacteria, accelerating CO2 transport into the cell. Overall, CO2 sink was stronger on Chlorophyta dominance days than on Cyanobacteria dominance days. This study emphasized the influence of algal phyla on CO2 fluxes, revealing the significant CO2 sink associated with Chlorophyta. Further research should investigate how to manipulate environmental factors to favor Chlorophyta growth and effectively reduce CO2 emissions.

Determination of morphine sulfate anti-pain drug solubility in supercritical CO2 with machine learning method.

Accurate solute solubility measuring and modeling in supercritical carbon dioxide (ScCO2) would address the best working conditions and thermodynamic boundaries for material processing with this type of fluid. Theory- and data-driven methods are two general modeling approaches. Using theory-driven methods, the solubility is estimated based on the principles of thermodynamics, while data-driven methods are developed by training the algorithms. Despite acceptance of each of these methods, more experimental solubility data are still needed to promote modeling performances. In this study, for the first time, solubility of morphine sulfate is determined and modeled by a set of 13 semi-empirical (theory-driven) and random forest (data-driven) models. Using a laboratory system with an ultraviolet-visible (UV-Vis) spectroscopy, the experimental solubilities including 48 data points were obtained at different temperatures (308-338 K) and pressures (12-27 MPa). The minimum (0.806 × 10-5) and maximum (5.902 × 10-5) equilibrium mole fractions were observed at working pressures of 12 and 27 MPa, respectively, both at the same temperature of 338 K. It was indicated that random forest model (with AARD% of 1.29%) had an excellent predictive performance against semi-empirical models (with AARD% from 9.33 to 19.76%). The results showed that solute molecular weight had the highest effect on random forest modeling. Using modeling results from Chrastil and Bartle models, total and vaporization enthalpies of dissolution of morphine sulfate in ScCO2 were found to be 35.12 and 59.04 kJ/mole, respectively.

Effect of niobium addition over Ni/MCM-41 catalysts for dry reforming of biogas.

This work aimed to evaluate the effect of niobium addition on nickel-based catalysts and their performance in dry reforming reactions to produce syngas (H2 and CO). Different quantities of Nb2O5 (5, 10, and 20% w/w) were used to prepare the catalysts, while a fixed content of Ni was applied (20%). The catalysts were supported on MCM-41. Physical, chemical, and morphological analyses were conducted to assess the characteristics of the materials. The produced Nb-Ni catalysts were applied in dry reforming reactions at 800 °C for 12 h. The dry reforming results indicated that the catalyst with 10% Nb-Ni demonstrated the best conversion of CH4 and CO2 (> 97%) and a significant H2 production (40%), with good stability during 12 h of reaction, while the catalyst with 5% Nb-Ni showed lower conversions and did not present good stability during the reaction. The catalyst with 5% Nb-Ni exhibited the highest production of H2 (44%), and the lowest of CO (50.87%), probably due to the presence of parallel reactions that increased H2 content and caused carbon (coke) formation. The characterization results of this material revealed the greatest formation of carbon on its surface. The presence of coke can prejudice the efficiency of the catalyst during a reaction and significantly reduce its lifetime. The catalyst with 10% Nb-Ni did not present coke formation, while the catalyst with 20% Nb-Ni showed carbon presence. The good dispersion of Ni on supports (Nb2O5 and SiO2/MCM-41) can explain the best behavior of 10% Nb-Ni for dry reforming reactions. X-ray diffractometry of the solids suggests the contribution of both metals (Ni and Nb) to the reforming process. From the obtained results, the catalyst with 10% Nb-Ni was indicated as the most favorable for dry reforming reactions among the studied materials, displaying good stability and conversion along with resistance to carbon formation.

Intraoperative end-tidal carbon dioxide levels are not associated with recurrence-free survival after elective pancreatic cancer surgery: a retrospective cohort study.

Background: Intraoperative end-tidal carbon dioxide concentrations (EtCO2) values are associated with recurrence-free survival after colorectal cancer surgery. However, it is unknown if similar effects can be observed after other surgical procedures. There is now evidence available for target EtCO2 and its relation to surgical outcomes following pancreatic cancer surgery. Methods: In this single-center, retrospective cohort study, we analyzed 652 patients undergoing elective resection of pancreatic cancer at Heidelberg University Hospital between 2009 and 2016. The entire patient cohort was sorted in ascending order based on mean intraoperative EtCO2 values and then divided into two groups: the high-EtCO2 group and the low-EtCO2 group. The pre-specified primary endpoint was the assessment of recurrence-free survival up to the last known follow-up. Cardiovascular events, surgical site infections, sepsis, and reoperations during the hospital stay, as well as overall survival were pre-specified secondary outcomes. Results: Mean EtCO2 was 33.8 mmHg ±1.1 in the low-EtCO2 group vs. 36.8 mmHg ±1.9 in the high-EtCO2 group. Median follow-up was 2.6 (Q1:1.4; Q3:4.4) years. Recurrence-free survival did not differ among the high and low-EtCO2 groups [HR = 1.043 (95% CI: 0.875-1.243), log rank test: p = 0.909]. Factors affecting the primary endpoint were studied via Cox analysis, which indicated no correlation between mean EtCO2 levels and recurrence-free survival [Coefficient -0.004, HR = 0.996 (95% CI:0.95-1.04); p = 0.871]. We did not identify any differences in the secondary endpoints, either. Conclusions: During elective pancreatic cancer surgery, anesthesiologists should set EtCO2 targets for reasons other than oncological outcome until conclusive evidence from prospective, multicenter randomized controlled trials is available.

Scaling CO2 Electrolyzer Cell Area from Bench to Pilot.

To contribute meaningfully to carbon dioxide (CO2) emissions reduction, CO2 electrolyzer technology will need to scale immensely. Bench-scale electrolyzers are the norm, with active areas <5 cm2. However, cell areas on the order of 100s or 1000s of cm2 will be required for industrial deployment. Here, we study the effects of increasing cell area, scaling over 2 orders of magnitude from a 5 cm2 lab-scale cell to an 800 cm2 pilot plant-scale cell. A direct scaling of the bench-scale cell architecture to the larger area results in a ∼20% drop in ethylene (C2H4) selectivity and an increase in the parasitic hydrogen (H2) evolution reaction (HER). We instrument an 800 cm2 electrolyzer cell to serve as a diagnostic tool and determine that nonuniformities in electrode compression and flow-influenced local CO2 availability are the key drivers of performance loss upon scaling. Machining of an initial 800 cm2 cell results in a standard deviation in MEA compression that is 7-fold that of a similarly produced 5 cm2 cell (0.009 mm). Using these findings, we redesign an 800 cm2 cell for compression tolerance and increased CO2 transport and achieve an H2 FE in the revised 800 cm2 cell similar to that of the 5 cm2 case (16% at 200 mA cm-2). These results demonstrate that by ensuring uniform compression and fluid flow, the CO2 electrolyzer area can be scaled over 100-fold and retain C2H4 selectivity (within 10% of small-scale selectivity).

Increasing electrochemical carbon dioxide reduction to methane via a novel copper-based conductive metal organic framework.

The development of a new system for the electrochemical carbon dioxide reduction reaction (ECO2RR) to methane (CH4) is challenging, and novel conductive metal organic frameworks (c-MOFs) for efficient ECO2RR to CH4 are critical to this system. Here, we report a novel c-MOF, copper-pyromellitic dianhydride-2-methylbenzimidazole (Cu-PD-2-MBI), in which the introduction of electron-withdrawing 2-methylbenzimidazole (2-MBI) into the copper-pyromellitic dianhydride (Cu-PD) interlayer elevated the valence of copper (Cu) ions, which improved the ECO2RR performance of Cu-PD-2-MBI. Cu-PD-2-MBI was tested in a flow cell, and the Faradaic efficiency of CH4 reached 73.7 %, with a corresponding partial current density of -428.3 mA·cm-2 at -1.3 V, which was higher than those of most reported Cu-based catalysts. Further exploration via theoretical calculations indicated that the intercalated 2-MBI in Cu-PD-2-MBI induced a shift in the d-band center in the Cu sites from -2.63 to -1.86 eV and reduced the formation energy of the *COOH and *CHO intermediates in the process of generating CH4 compared with those of the reference Cu-PD catalyst.

Bismuth oxide nanoflakes grown on defective microporous carbon endows high-efficient CO2 reduction at ampere level.

Carbon dioxide electroreduction is a green technology for artificial carbon sequestration, which is being delayed from industrialization due to the lack of efficient catalysts at high current conditions. Herein, the Bi2O3 nanoflakes were uniformly grown on a defective porous carbon (PC). This self-assembling Bi2O3/PC catalyst was applied to drive CO2 electroreduction at 1.0 A, 1.5 A and 2.0 A while the Faradaic efficiency of formate reaches 91.50 %, 86.30 % and 84.22 %, respectively. Density functional theory calculations revealed the intrinsic defect of carbon is able to give electron to Bi through O bridge, which increased the electron aggregation of Bi and lowered the generation energy barrier of *OCHO intermediate. Additionally, the unique 3D network of staggered Bi2O3 enhances the CO2 adsorption and favors the electron transportation. By integrating all above advantages into a solid electrolyte-type cell, we are able to produce pure formic acid in a rate of 15.48 mmol h-1 at ampere current.

Carbon dioxide as a sustainable reagent in circular hydrometallurgy.

This review highlights the use of CO2 as a reagent in hydrometallurgy, with emphasis on the new concept of circular hydrometallurgy. It is shown how waste CO2 can be utilised in hydrometallurgical operations for pH control or regeneration of acids for leaching. Metal-rich raffinate solutions generated after removal of the valuable metals can serve as feedstocks for mineral carbonation, providing alternative avenues for CO2 sequestration. Furthermore, CO2 can also be used as a renewable feedstock for the production of chemical reagents that can find applications in hydrometallurgy as lixiviant, as precipitation reagent or for pH control. Mineral carbonation can be combined with chemical reactions involving metal complexation reagents, as well as with solvent extraction processes for the concurrent precipitation of metal carbonates and acid regeneration. An outlook for future research in the area is also presented.

Evolution of CO2 flux over 60 years: Identifying source and sink changes caused by eutrophication of Hulun Lake.

Understanding the carbon cycling process and assessing the carbon sequestration potential in freshwater lakes relies heavily on their source-sink relationship. However, human activity and climate change have obscured the clarity of this relationship and its driving mechanisms, particularly in northern grassland lakes. This study focused on Hulun Lake, the largest grassland lake in northern China, to quantitatively analyze the carbon dioxide exchange flux (FCO2) at the water-air interface from 1963 to 2023. The analysis revealed significant seasonal, interannual, and decadal variations in the FCO2. Over the past 60 years, FCO2 varying significant in seasons and years has notably decreased, averaging 0.324 ± 0.106 gC·m-2·d-1. Notably, there was a qualitative change in FCO2 from "sink" (0.161 ± 0.109 gC·m-2·d-1) to "source" (-0.130 ± 0.087 gC·m-2·d-1)between 2019 and 2020. From 1963 to 2019, the lake acted as a CO2 source, releasing an average flux of 0.438 ± 0.111 gC·m-2·d-1. During this period, FCO2 was the highest in spring, followed by summer, and the lowest in autumn and winter when the lake was covered by ice. In 2020, the lake transitioned into a CO2 sink with an average FCO2 of -0.248 ± 0.042 gCm-2·d-1 from 2020 to 2023. During this period, FCO2 peaked in autumn, followed by summer and spring, and was lowest in winter when the lake was ice covered. A structural model equation (SEM) was employed to analyze the effects of various factors, including physical, chemical, and biological aspects, on FCO2 and the source-sink pattern of Hulun Lake. This study suggested that lake eutrophication, compounded by global warming, may be the primary driving force behind these changes. Rising temperatures and eutrophication enhanced the primary productivity of the lake. The amount of CO2 fixed through photosynthesis surpassed that emitted by respiration. Consequently, the eutrophication may alter the CO2 exchange pattern in Hulun Lake, shifting it from a "source" to a "sink".

Carbon dioxide capture, sequestration, and utilization models for carbon management and transformation.

The elevated level of carbon dioxide in the atmosphere has become a pressing concern for environmental health due to its contribution to climate change and global warming. Simultaneously, the energy crisis is a significant issue for both developed and developing nations. In response to these challenges, carbon capture, sequestration, and utilization (CCSU) have emerged as promising solutions within the carbon-neutral bioenergy sector. Numerous technologies are available for CCSU including physical, chemical, and biological routes. The aim of this study is to explore the potential of CCSU technologies, specifically focusing on the use of microorganisms based on their well-established metabolic part. By investigating these biological pathways, we aim to develop sustainable strategies for climate management and biofuel production. One of the key novelties of this study lies in the utilization of microorganisms for CO2 fixation and conversion, offering a renewable and efficient method for addressing carbon emissions. Algae, with its high growth rate and lipid contents, exhibits CO2 fixation capabilities during photosynthesis. Similarly, methanogens have shown efficiency in converting CO2 to methane by methanogenesis, offering a viable pathway for carbon sequestration and energy production. In conclusion, our study highlights the importance of exploring biological pathways, which significantly reduce carbon emissions and move towards a more environmentally friendly future. The output of this review highlights the significant potential of CCSU models for future sustainability. Furthermore, this review has been intensified in the current agenda for reduction of CO2 at considerable extends with biofuel upgrading by the microbial-shift reaction.

Synthesis and Electrochemical Study of Gold(I) Carbene Complexes.

In this work, we have prepared and characterized some gold compounds wearing a N-heterocyclic carbene (NHC) ligand as well as alkynyl derivatives with different substituents. The study of their electrochemical behavior reveals that these complexes show an irreversible wave at potentials ranging between -2.79 and -2.91 V, referenced to the ferrocenium/ferrocene pair. DFT calculations indicate that the reduction occurs mainly on the aryl-C≡C fragment. The cyclic voltammetry experiments under CO2 atmosphere show an increase in the faradaic current of the reduction wave compared to the experiments under argon atmosphere, indicating a possible catalytic activity towards the carbon dioxide reduction reaction (CO2RR).

Molecular insights into the performance of promoters for carbon dioxide hydrate.

Hydrate-based CO2 storage is a cost-effective and environmentally friendly approach to reduce carbon emission, and the addition of hydrate promoters has shown a promising avenue for enhancing CO2 hydrate formation. In this work, the promotion mechanism and promotion performance of five different hydrate promoters (denoted as DIOX, CP, THF, THP, and CH) were investigated and compared by first-principles calculations and molecular dynamics simulations. The results show that the hydrate promoters prefer to singly occupy 51264 cages of the sII hydrate, and CO2 molecules can singly occupy 512 cage or multiply occupy 51264 cages. The cohesive energy density indicates that the optimum CO2 storage capacity can reach up to ∼28 wt%. The stabilization effects of hydrate promoters on the hydrate stability should follow the order of CP > CH > DIOX > THF ≈ THP. The hydrate promoters can increase the water-water interactions, and the molecular diffusivity shows that the dynamic stability of the hydrates is THP ≈ CH > CP > DIOX > THF. Further, the hydrate promoters can accelerate the hydrate formation kinetics, which reduce the induction time and increase the nucleation and growth process.

The Development of Metal-Free Porous Organic Polymers for Sustainable Carbon Dioxide Photoreduction.

A viable tactic to effectively address the climate crisis is the production of renewable fuels via photocatalytic reactions using solar energy and available resources like carbon dioxide (CO2) and water. Organic polymer material-based photocatalytic materials are thought to be one way to convert solar energy into valuable chemicals and other solar fuels. The use of porous organic polymers (POPs) for CO2 fixation and capture and sequestration to produce beneficial compounds to reduce global warming is still receiving a lot of interest. Visible light-responsive organic photopolymers that are functionally designed and include a large number of heteroatoms and an extended π-conjugation allow for the generation of photogenerated charge carriers, improved absorption of visible light, increased charge separation, and decreased charge recombination during photocatalysis. Due to their rigid structure, high surface area, flexible pore size, permanent porosity, and adaptability of the backbone for the intended purpose, POPs have drawn more and more attention. These qualities have been shown to be highly advantageous for numerous sustainable applications. POPs may be broadly categorized as crystalline or amorphous according to how much long-range order they possess. In terms of performance, conducting POPs outperform inorganic semiconductors and typical organic dyes. They are light-harvesting materials with remarkable optical characteristics, photostability, cheap cost, and low cytotoxicity. Through cocatalyst loading and morphological tweaking, this review presents optimization options for POPs preparation techniques. We provide an analysis of the ways in which the preparative techniques will affect the materials' physicochemical characteristics and, consequently, their catalytic activity. An inventory of experimental methods is provided for characterizing POPs' optical, morphological, electrochemical, and catalytic characteristics. The focus of this review is to thoroughly investigate the photochemistry of these polymeric organic photocatalysts with an emphasis on understanding the processes of internal charge generation and transport within POPs. The review covers several types of amorphous POP materials, including those based on conjugated microporous polymers (CMPs), inherent microporosity polymers, hyper-crosslinked polymers, and porous aromatic frameworks. Additionally, common synthetic approaches for these materials are briefly discussed.

A Review of Gas Sensors for CO2 Based on Copper Oxides and Their Derivatives.

Buildings worldwide are becoming more thermally insulated, and air circulation is being reduced to a minimum. As a result, measuring indoor air quality is important to prevent harmful concentrations of various gases that can lead to safety risks and health problems. To measure such gases, it is necessary to produce low-cost and low-power-consuming sensors. Researchers have been focusing on semiconducting metal oxide (SMOx) gas sensors that can be combined with intelligent technologies such as smart homes, smart phones or smart watches to enable gas sensing anywhere and at any time. As a type of SMOx, p-type gas sensors are promising candidates and have attracted more interest in recent years due to their excellent electrical properties and stability. This review paper gives a short overview of the main development of sensors based on copper oxides and their composites, highlighting their potential for detecting CO2 and the factors influencing their performance.