Poplar Catkins Research Articles

Scalable and sustainable radiative cooling enabled by renewable poplar catkin-derived films

Passive radiative cooling is a vital strategy for mitigating the greenhouse effect. However, the widespread use of synthetic plastics as the primary constituent raises environmental concerns of plastic waste. Addressing these challenges necessitates the development of radiative cooling materials based on natural and renewable resources. Herein, we utilize the abundant but underutilized poplar catkins, which are currently perceived as harmful, to fabricate a poplar catkin-derived (PC) film for radiative cooling. The PC film exhibits exceptional cooling performance, with a maximum cooling power of 75.3 W m−2 under an average sunlight intensity of 819 W m−2. Remarkably, the PC film achieves a sub-ambient temperature reduction of 6.2 °C during 9:00–13:00, within a similar solar radiation intensity. Additionally, the PC film possesses outstanding properties, including UV resistance, mold resistance, and renewability. Even after multiple regeneration cycles, the film experiences only marginal decreases of 0.9 % in sunlight reflectance and 1.4 % in infrared emissivity (8–13 μm). Furthermore, the resulting film demonstrates superior resistance to mildew compared to wood, highlighting its potential for long-term usability. This work not only addresses the environmental concerns associated with synthetic plastics but also harnesses the untapped potential of readily available natural resources to develop sustainable radiative cooling materials.

Porous Carbon Derived from Poplar Catkins and Its High-performance CO2 Capture

Porous Carbon Derived from Poplar Catkins and Its High-performance CO2 Capture

Function and molecular mechanism of a poplar placenta limited MIXTA gene in regulating differentiation of plant epidermal cells

The placenta in fruits of most plants either desiccate and shrink as the fruits mature or develop further to form the fleshy tissues. In poplars, placental epidermal cells protrude collectively to produce catkin fibers. In this study, three carpel limited MIXTA genes, PdeMIXTA02, PdeMIXTA03, PdeMIXTA04, were find to specifically expressed in carpel immediately after pollination. Heterologous expression of the three genes in Arabidopsis demonstrated that PdeMIXTA04 significantly promoted trichomes density and could restore trichomes in the trichomeless mutant. By contrast, such functions were not observed with PdeMIXTA02, PdeMIXTA03. In situ hybridization revealed that PdeMIXTA04 was explicitly expressed in poplar placental epidermal cells. We also confirmed trichome-specific expression of the PdeMIXTA04 promoter. Multiple experimental proofs have confirmed the interaction between PdeMIXTA04, PdeMYC and PdeWD40, indicating PdeMIXTA04 functioned through the MYB-bHLH-WD40 ternary complex. Our work provided distinctive understanding of the molecular mechanism triggering differentiation of poplar catkins.

The integration of Triazine-based porous organic polymer with bio-waste poplar catkin as water-floatable photocatalyst

Floating photocatalysis material has a big advantage over powdery suspending one for deep purification of pollutants in colored wastewater, in consideration of its excellent flexibility, high light-harvesting, and convenient recycling in suspension solution systems. As a result, the design and synthesis of floating photocatalyst are of great importance. Herein, we concentrate on the preparation of metal-free triazine-based porous organic polymer (POP) as a visible-light photocatalyst on biomass waste poplar catkins (PCs) to construct a reusable floating photocatalysis system via a soft synthesis, that is, trigonal-symmetrical melamine (M) is coupled with triformylphloroglucinol (TFP) monomer to obtain photoactive conjugated POPM-TFP loaded on soft and light PC microfibers (Named as PC/POPM-TFP). When PC/POPM-TFP (20 mg) is floated on the polluted water, it can convert 100% Cr(VI) (50 mL, 10 mg/L) in 80 min into Cr(III) species which are then partly synchronously immobilized (56.9%) to lessen the rerelease of Cr element, or degrade 100% methylene blue (MB, 60 mL, 10 mg/L) after 100 min of visible-light irradiation. Moreover, the film-like flexible self-supporting PC/POPM-TFP also exhibits well catalytic activities and excellent reusability for multipurpose water purification under real natural conditions. The molecular oxygen in the solution gains electrons from PC/POPM-TFP to generate •O2–, which is involved in photoreduction of Cr(VI) besides photo-induced electrons, and mainly contributes to photooxidation degradation of MB. The proposal of floating PC/POPM-TFP not only avoids the risks to release metal ions into water during utilization, which will cause secondary pollution, but also provides an alternative method to overcome the limitations of powdery photocatalyst for recycling. Overall, this study assists the assembly of green floating photocatalysis systems to allow a versatile solid surface activation for establishing more energy efficient and robust catalysis process under visible light.

NiCo layer double hydroxide/biomass-derived interconnected porous carbon for hybrid supercapacitors

Poplar catkins, as a typical biotemplate, has great potential for designing of interconnected porous carbon (IPC) toward hybrid supercapacitors. Herein, NiCo layered double hydroxide (LDH)/IPC composites were prepared and utilized as competitive materials of supercapacitor electrodes. NiCo LDH/IPC electrode displays the better electrochemical performance (209.7 mAh g − 1 at 1 A g − 1) than pure NiCo LDH electrode (148.6 mAh g − 1 at 1 A g − 1). Furthermore, the hybrid supercapacitors (HSCs) were assembled using a positive electrode of as-prepared NiCo LDH/IPC and a negative electrode of IPC. The NiCo LDH/IPC||IPC provides the higher specific energy of 29.6 Wh kg−1 and better cycling stability than NiCo LDH||IPC, which is ascribed to the introducing of IPC with advanced porous structure, improving the electrochemical performance.

Functionalised poplar catkins aerogels: Synthesis, characterisation and application to adsorb Cu(II) and Pb(II) from wastewater

Massive poplar catkins (PCs) bring up a range of serious issues, including sneezing, skin allergy and even forest fire. In this study, porous and shape-adjustable magnetic aerogel based on PCs, chitosan and Fe3O4 (PCCM) were synthesised for the adsorption of Cu(II) and Pb(II) from wastewater. SEM, XRD, FTIR and XPS were used to analyse the physicochemical properties of PCCM aerogel. The adsorption kinetics of Cu(II) and Pb(II) were conformed to the pseudo-second order kinetic and Langmuir model. The maximum adsorption capacitiy of PCCM aerogel for Cu(II) and Pb(II) were 81.3 mg g−1 and 112.3 mg g−1, respectively.

Gene expression trajectories during male and female reproductive development in balsam poplar (Populus balsamifera L.)

Plant reproductive development from the first appearance of reproductively committed axes through to floral maturation requires massive and rapid remarshalling of gene expression. In dioecious species such as poplar this is further complicated by divergent male and female developmental programs. We used seven time points in male and female balsam poplar (Populus balsamifera L.) buds and catkins representing the full annual flowering cycle, to elucidate the effects of time and sex on gene expression during reproductive development. Time (developmental stage) is dominant in patterning gene expression with the effect of sex nested within this. Here, we find (1) evidence for five successive waves of alterations to the chromatin landscape which may be important in setting the overall reproductive trajectory, regardless of sex. (2) Each individual developmental stage is further characterized by marked sex-differential gene expression. (3) Consistent sexually differentiated gene expression regardless of developmental stage reveal candidates for high-level regulators of sex and include the female-specific poplar ARR17 homologue. There is also consistent male-biased expression of the MADS-box genes PISTILLATA and APETALA3. Our work provides insights into expression trajectories shaping reproductive development, its potential underlying mechanisms, and sex-specific translation of the genome information into reproductive structures in balsam poplar.

Bioaccessibility of metals/metalloids in willow catkins collected in urban parks of Beijing and their health risks to human beings

Air pollution and its resulting health risks in Beijing City have been widely investigated by scientists and administrators. However, the health risks caused by willow and poplar catkins in April and May (known as “spring snow”) have been rarely reported. Poplar and willow are the two common trees in Beijing City that generate many whirling catkins in the air. The chemical composition of catkins remains unknown. In this study, catkins and dust samples were collected in several parks in Beijing. The total concentrations of metals/metalloids in catkins measured through inductively coupled plasma mass spectrometry were generally lower than those of the corresponding dust samples, and they were lower than the risk control standard for soil contamination of development land. The simulated rain and lung fluid extraction rates of catkin samples were significantly higher than those of the dust samples. The concentration of extracted Pb and Zn using simulated rainwater exceeded the environmental quality standards for surface water (0.1 and 2.0 mg/L for Pb and Zn, respectively), indicating the possibility of runoff pollution. Scanning electron microscopy images showed that fine particles (<10 μm) are attached to the surface of catkins. Therefore, the metals/metalloids in fine particles adsorbed by the catkin samples possess higher bioaccessibility than that in the dust samples based on different sizes of particles. A significant correlation is found between Pb in catkin and Pb in dust. Therefore, attention should be paid to the possible increase in metal/metalloid concentrations in catkins planted in contaminated areas.

Ultrathin NiCo2O4 nanosheets assembled on biomass-derived carbon microsheets with polydopamine for high-performance hybrid supercapacitors

The hierarchical architecture of biomass activated carbon and metal oxides has attracted wide attention in the field of energy storage owing to its high specific surface area, good electrical conductivity, low cost and environmental friendliness. Herein, biomass carbon-based porous microsheets with thickness of 150–200 nm are obtained by ultrasonic crushing the carbonized poplar catkins (PC) micro-hollow fibers. The carbon microsheets were modified with polydopamine and further deposited with ultrathin nickel cobaltite nanosheets (NiCo2O4 NSs) to form a NiCo2O4 shell-carbon core sandwich composite. Benefiting from its characteristics, as-prepared hybrid electrodes exhibit significantly enhanced specific capacity (922.9C g−1 at 1 A g−1), excellent rate capability and good cycling stability. Furthermore, the hybrid supercapacitor was also fabricated with NiCo2O4 NSs@PD-PC and polydopamine-modified poplar catkins (PD-PC) carbon materials as positive electrode and negative electrode, respectively. It shows remarkable energy-storage characteristics, such as a high energy density of 39.1 W h kg−1 at the power density of 799.9 W kg−1, only 4.5% capacity loss after 5000 cycles, as well as a wide potential window of 0–1.6 V. Such excellent performance makes poplar catkins-derived carbon-based electrodes promise as one of the attractive candidates for high performance energy storage devices.

Enhanced acetone sensing properties of hollow SnO2 fibers using poplar catkins as a bio-template

Porous hollow SnO2 fibers with an average crystallite size of 6.1 ± 0.5 nm were synthesized by a facile solvothermal method using poplar catkins as a biological template. The synthesized hollow SnO2 fibers were characterized by X-ray photoelectron spectroscopy, powder X-ray diffraction, transmission electron microscopy, nitrogen adsorption/desorption measurements, and high-resolution scanning electron microscopy. Results showed that the products presented a high specific surface area of 110.1 m2/g and maintained mesoporous structures with a narrow pore size concentrated at 4.9 nm. The results of gas sensing tests showed that the response of SnO2 fibers was about 1016.4 and 7.0 to 100 ppm and 1 ppm acetone at 100 °C, respectively, indicating that the products exhibited excellent gas sensing performance towards acetone.

Poplar catkin-derived self-templated synthesis of N-doped hierarchical porous carbon microtubes for effective CO2 capture

Poplar catkins are an environmental pollutant because they can trigger sneezing, shortness of breath, skin allergy and even cause forest fire. It is very attractive to discover ways for reducing the threats of poplar catkins to the environment and human health and even to convert poplar catkins into useful materials. Herein we report on a facile and cost-efficient strategy for the synthesis of hierarchical porous carbon microtubes using poplar catkins as the carbon source. The synthesis involves pre-carbonization and subsequent ZnCl2 activation. The resultant materials not only inherit the natural tubular morphology of poplar catkins, but also develop a hierarchical porous structure, with nitrogen from the biomass being self-doped in the resultant carbon skeleton. The hierarchical porosity, especially the microporosity with the pore size from 0.5 to 1 nm, surface structure, tube wall thickness and nitrogen content can be readily controlled by adjusting the activation temperature and the ZnCl2-to-precursor mass ratio. The produced materials exhibit an excellent CO2 capture capacity. The optimal sample activated at 800 °C with a ZnCl2-to-precursor mass ratio of 4:1 shows an extraordinarily high CO2 adsorption capacity of 6.22 and 4.05 mmol g−1 at 273 and 298 K, respectively, at 1 bar of CO2. Furthermore, the material also displays an excellent recyclability and CO2/N2 selectivity. Our approach not only relieves the environmental pollution of poplar catkins but also leads to the production of a high-performance CO2 adsorbent, which is promising for industrial CO2 capture and separation. It therefore demonstrates an example of trash-to-treasure transformation.

Uniform CdS-decorated carbon microsheets with enhanced photocatalytic hydrogen evolution under visible-light irradiation

Large-scale production of clean and renewable fuels is crucial for satisfying the world's energy needs, and hydrogen evolution via photo-driven water splitting stands as a prime candidate to fill this need. In present work, we converted carbonized poplar catkins (CPC) microtubes into microsheets by ultrasonic crushing and subsequently deposited CdS nanoparticles on the microsheets to synthesize the CdS/carbon (CdS/CPC) photocatalyst for photo-driven hydrogen evolution. The carbon microsheets were ∼160 nm thick and 1–20 μm wide in dimensions, and CdS nanoparticles with a diameter of ∼20 nm were homogeneously dispersed on the microsheets. The CdS/CPC composites showed a higher visible-light absorption and larger photocurrent density compared with pure CdS. The as-prepared composites exhibited excellent photocatalytic activity for water splitting, and the H2-evolution rate was up to 5367 μmol g−1 h−1, approximately 7.8 times that of pure CdS. Moreover, CdS/CPC-2 can retain 93.8% of its original H2-evolution rate after 4-cycle continuous catalyzing last for 16 h. The extremely high activity of CdS/CPC can be attributed to its lower interfacial charge-transfer resistance and the effective separation of photo-induced electrons because of two-dimensional structure. A combination of low-cost production and excellent photocatalytic H2-evolution demonstrates the potential application of bio-derived carbon-based microsheets for noble-metal-free photocatalyst.

Nanoporous carbons derived from poplar catkins for high performance supercapacitors with a redox active electrolyte of p-phenylenediamine

Nanoporous carbons (NPCs) have been successfully prepared from poplar catkins (PCs) as a sustainable and renewable carbon source by a facile carbonization and subsequent KOH activation procedure. The KOH-activated NPCs at 800 °C (NPC800) exhibits a hierarchical porous structure containing macroporous frameworks and microporous textures, with a high specific surface area of 1251.5 m2 g−1 and a large pore volume up to 0.85 cm3 g−1. In addition, a novel redox-active electrolyte through introducing a redox-mediator (p-phenylenediamine, PPD) into KOH electrolytes was used to improve the electrochemical performance of the NPCs-based supercapacitors. The NPC800 exhibits a high specific capacitance of 557 F g-1 at 0.1 A g−1, a good rate capability of 254 F g-1 at 10 A g−1 and excellent cycle stability with 77.4% capacitance retention after 500 cycles at 1 A g−1. With a favorable capacitive performance, the waste biomass PCs could be a new source of carbonaceous materials for high performance and low-cost supercapacitors.

P.2.h.011 - Mania associated with digoxin: case description and literature review

Nanoporous carbons (NPCs) have been successfully prepared from poplar catkins (PCs) as a sustainable and renewable carbon source by a facile carbonization and subsequent KOH activation procedure. The KOH-activated NPCs at 800 °C (NPC800) exhibits a hierarchical porous structure containing macroporous frameworks and microporous textures, with a high specific surface area of 1251.5 m2 g−1 and a large pore volume up to 0.85 cm3 g−1. In addition, a novel redox-active electrolyte through introducing a redox-mediator (p-phenylenediamine, PPD) into KOH electrolytes was used to improve the electrochemical performance of the NPCs-based supercapacitors. The NPC800 exhibits a high specific capacitance of 557 F g-1 at 0.1 A g−1, a good rate capability of 254 F g-1 at 10 A g−1 and excellent cycle stability with 77.4% capacitance retention after 500 cycles at 1 A g−1. With a favorable capacitive performance, the waste biomass PCs could be a new source of carbonaceous materials for high performance and low-cost supercapacitors.

A Valuable Biochar from Poplar Catkins with High Adsorption Capacity for Both Organic Pollutants and Inorganic Heavy Metal Ions

In this paper, biochar derived from poplar catkins was used as an economical and renewable adsorbent for adsorption organic and inorganic pollutants such as, dyes, organic compounds, and heavy metal ions from wastewater. Mesoporous activated carbonized poplar catkins (ACPCs) were produced from char as a by-product by carbonized poplar catkins (CPCs). With their high surface area, ACPCs exhibited the maximum adsorption capacities of 71.85 and 110.17 mg/g for the removal of inorganic U(VI) and Co(II). Compared other biochars adsorbents, ACPCs can also adsorb organic pollutants with the maximum adsorption capacities of 534, 154, 350, 148 and 384 mg/g for methylene blue (MB), methyl orange (MO), Congo red (CR), chloramphenicol (CAP) and naphthalene. The adsorption of organic pollutants was fitted with pseudo-first order, pseudo-second order, and intra-particle diffusion kinetic models figure out the kinetic parameters and adsorption mechanisms. Langmuir adsorption isotherm was found to be suitable for Co(II) and U(VI) adsorption and thermodynamic studies indicated adsorption processes to be endothermic and spontaneous. The adsorption process includes both outer-sphere surface complexes and hydrogen-bonding interactions. The results showed that biochar derived from poplar catkins was a potential material to remove pollutants in wastewater.

Superior supercapacitive performance of hollow activated carbon nanomesh with hierarchical structure derived from poplar catkins

The hollow activated carbon nanomesh (PCACM) with a hierarchical porous structure is derived from biowaste-poplar catkins by in-situ calcination etching with Ni(NO3)2·6H2O and KOH in N2 flow combined with an acid dissolution technique. This procedure not only inherits the natural tube morphology of poplar catkins, but also generates a fascinating nanomesh structure on the walls. PCACM possesses a large specific surface area (SBET = 1893.0 m2 g−1) and high total pore volume (Vp = 1.495 cm3 g−1), and displays an exciting meso-macoporous structure with a concentrated pore size distribution of 4.53 nm. The specific capacitance of PCACM is as high as 314.6 F g−1 at 1.0 A g−1 when used as the electrode materials for supercapacitor. Furthermore, the symmetric supercapacitor of PCACM with 1.0 M Na2SO4 solution as the electrolyte displays a high energy density of 20.86 Wh kg−1 at a power density of 180.13 W kg−1 within a wide voltage rage of 0–1.8 V, which is comparable or even obviously higher than those of other biomass derived carbon reported. It is noteworthy that PCACM also exhibits superior cycling stability and coulombic efficiency. The excellent electrochemical behaviors enable PCACM to be a promising electrode material for supercapacitors.

A versatile biomass derived carbon material for oxygen reduction reaction, supercapacitors and oil/water separation

Directly pyrolyzing biowastes has attracted intensive interest, probably because this economical and facile method provides an efficient and versatile platform for synthesizing functional carbons. This study describes the synthesis of different functional carbons from poplar catkins via different processes for multi-purpose applications. Nitrogen and oxygen dual-doped carbon (NODC-800) derived from catkins delivers superior electrochemical characteristics as oxygen reduction reaction (ORR) catalyst in alkaline fuel cell to that of commercial Pt/C in terms of catalytic activity, stability, resistance to methanol cross-over and CO poisoning. In addition, NODC-800 exhibits a high capacity (~251Fg−1 at 0.5Ag−1) with nearly 100% retention rate after 1000 cycles as supercapacitors electrodes. An oleophylic carbon aerogel derived from catkins is proven to be superoleophilic and porous enough to “wet” with oils and organic liquids and repel water completely to achieve oil/water separation. This work is a successful case to take full advantage of raw materials from nature via multiple technologies to achieve energy sustainable development and protect environmental from oils and organic solvents spill.

Activated Carbon Microtubes Prepared from Plant Biomass (Poplar Catkins) and Their Application for Supercapacitors

Abstract Activated carbon microtubes (CMTs) have been prepared from poplar catkins by chemical activation with ZnCl2. The as-synthesized porous CMTs have large inner tubes of several micrometers, large Brunauer–Emmett–Teller surface areas of up to 1400 m2 g−1, a complex porous structure with predominant micropores (≥80 vol %), and small amount of mesopores (≤20 vol %). Two-electrode supercapacitor cells constructed with the activated CMTs yield a specific capacitance of 206 F g−1 and an energy density of 7.5 W h kg−1 with aqueous electrolyte, values that are much higher than those of an activated carbon (160 F g−1, 5.5 W h kg−1).

Preparation of Three-Dimensional Carbon Microtube/Carbon Nanotube Composites and Their Application in Supercapacitor

Carbon microtubes (CMTs) were prepared by the carbonization of poplar catkins according to their natural microtubular structure.The CMTs were then used as the substrate for growing carbon nanotubes (CNTs) by chemical vapor deposition.The prepared three-dimensional CMT/CNT composites were characterized by scanning electron microscopy (SEM),transmission electron microscopy (TEM),X-ray diffraction (XRD),and Raman spectroscopy.Two-electrode supercapacitor cells constructed with the CMT/CNT showed a specific capacitance of 77 F·g-1 with 1mol·L-1Li2SO4 electrolyte,which is much higher than that for CMTs (23 F·g-1).

The production of carbon microtubes by the carbonization of catkins and their use in the oxygen reduction reaction

Willow or poplar catkins were carbonized to prepare carbon microtubes (CMTs) due to their natural micro-tubular structure. After carbonization at temperatures of 550–950 °C, CMTs with outer and inner diameters of 4–8 and 3–7 μm were obtained. In addition to having a large and accessible inner tube, a small amount of nitrogen (∼1.8 at.%) and phosphorus (∼0.4 at.%) dopants cause CMTs prepared at 750 °C to be a cheap metal-free catalyst with good catalytic activity in the oxygen reduction reaction.