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Highlights Two-dimensional mono- and few-layered Ti 3 CNT x MXene nanosheets with extremely high nitrogen content were synthesized. Better performance for hydrogen evolution reaction (HER) than Pt/C catalyst in acidic, neutral and alkaline solutions. Exceptional performance of HER in both acidic and alkaline solutions. A large current density (> 500 mA cm −2 ) has been achieved for HER. Transition metal carbides, known as MXenes, particularly Ti 3 C 2 T x , have been extensively explored as promising materials for electrochemical reactions. However, transition metal carbonitride MXenes with high nitrogen content for electrochemical reactions are rarely reported. In this work, transition metal carbonitride MXenes incorporated with Pt-based electrocatalysts, ranging from single atoms to sub-nanometer dimensions, are explored for hydrogen evolution reaction (HER). The fabricated Pt clusters/MXene catalyst exhibits superior HER performance compared to the single-atom-incorporated MXene and commercial Pt/C catalyst in both acidic and alkaline electrolytes. The optimized sample shows low overpotentials of 28, 65, and 154 mV at a current densities of 10, 100, and 500 mA cm −2 , a small Tafel slope of 29 mV dec −1 , a high mass activity of 1203 mA mg Pt −1 and an excellent turnover frequency of 6.1 s −1 in the acidic electrolyte. Density functional theory calculations indicate that this high performance can be attributed to the enhanced active sites, increased surface functional groups, faster charge transfer dynamics, and stronger electronic interaction between Pt and MXene, resulting in optimized hydrogen absorption/desorption toward better HER. This work demonstrates that MXenes with a high content of nitrogen may be promising candidates for various catalytic reactions by incorporating single atoms or clusters.

Photocatalytic hydrogen production via solar energy is considered one of the most strategic ways to produce renewable energy. However, expensive Pt is normally used as the cocatalyst during photocatalysis, which prevents commercialization. Therefore, extensive research has been performed to seek abundant and low‐cost alternative catalysts. In this work, MoS2 quantum dots (QDs) synthesized by a hydrothermal method are incorporated with graphitic carbon nitride to form a heterostructure for photocatalytic hydrogen evolution. MoS2 QDs/g‐C3N4 heterostructure containing 5% and 10% MoS2 QDs exhibited a high hydrogen production of 140 and 152 µmol h−1g−1, respectively, demonstrating the potential of MoS2 as an effective economic cocatalyst. Detailed investigations indicate that incorporating MoS2 QDs with carbon nitride to form heterostructure reduces the bandgap, suppresses the recombination, and enhances electron kinetic energy resulting from the anti‐Stoke effect, thus leading to better performance for hydrogen evolution. MoS2/g‐C3N4 heterostructure shows enhanced photocatalytic hydrogen evolution without Pt as the cocatalyst. The enhanced performance is due to the electric field induced in the interface of the heterostructure, which suppresses the recombination of electrons and holes, and the anti‐Stoke effect induced energy transfer, leading to higher kinetic energy of the excited electrons.

Graphitic carbon nitride (g‐C3N4) has attracted enormous attention as a photocatalyst due to its appropriate bandgap, high chemical stability, and visible light response. However, it is still challenging to synthesize highly crystalline g‐C3N4, favoring the separation of photogenerated electron–hole pairs and promoting improved photocatalytic activity. Herein, we report a novel approach to achieve highly crystalline g‐C3N4 by simply pressing sodium chloride and carbon nitride into a pellet followed by heat treatment, which is different from conventional molten salt methods. The resulting g‐C3N4 has an optimum band structure that benefits enhanced light absorption and charge separation efficiency. The intimate contact between sodium chloride and carbon nitride in the pressed pellet facilitates the diffusion of sodium ions and increases the material's resistance to high annealing temperatures, leading to improved crystallinity. The photocurrent response of this highly crystalline material under visible light irradiation is approximately four times higher than that of its bulk counterpart, resulting in a hydrogen production rate of up to 650 μmol g−1 h−1 (10% TEOA). This work paves a new path in designing novel carbon nitrides with enhanced photoelectrochemical and photocatalytic performance. Carbon nitride mixed with sodium chlorine is pressed into a pellet with a subsequently heat treatment. The obtained carbon nitride achieves improved crystallinity and enhanced hydrogen evolution reaction.

Developing a durable and efficient oxygen evolution reaction (OER) catalyst without noble metals is essential for the economical and sustainable production of hydrogen by alkaline water electrolysis. Recent studies have advocated triggering the lattice oxygen mechanism (LOM) to reduce the overpotential of catalysis and overcome the inherent limitations of the adsorbate evolution mechanism (AEM). Herein, we explored a facile and scalable method for synthesizing an iron‐rich nickel‐layered double hydroxide (NiFe‐LDH) with a unique hollow nanocapsule morphology using a metal‐organic framework (MOF) MIL‐88A as a sacrificial template for OER. The transformation of the MOF into hollow NiFe‐LDH provides abundant lattice oxygen defects and alters the Fermi level of O 2p, triggering LOM. As a result, the material exhibited outstanding OER performance, with a low overpotential of 244 mV at 10 mAcm−2, and excellent long‐term durability. Ex‐situ X‐ray Photoelectron Spectroscopy (XPS) analysis of the catalyst before and after the OER reaction revealed a high density of surface oxygen defects in the Fe‐rich NiFe‐LDH, which is a prerequisite for LOM activation. Also, through in‐situ Raman spectroscopy, which monitored the appearance of superoxide intermediates (1040–1250 cm−1), revealed strong evidence for the involvement of the single metal site LOM and dual metal site LOM pathways in the OER. The presence of Fe2+ and Fe3+ in Fe‐rich NiFe‐LDH and the possible LOM mechanism were further evaluated using computational analyses. Fe‐rich NiFe‐LDH catalysts derived from MOFs, showing superior OER activity via lattice oxygen mechanism activation.

Skin cancer has emerged as one of the leading types of cancers in the world, causing a high impact on the global burden of health and the economy. Basal cell and squamous cell carcinoma are the localized forms of skin cancer with a high prevalence and can be treated with a high success rate. However, melanoma, a rare type of skin cancer with a high mortality rate, can metastasize and invade other parts of the body. Various skin cancer treatment approaches have been developed and advanced from localized to systemic treatment over the years to improve the low success rate associated with skin cancer, especially metastatic melanoma. The systemic treatment of skin cancer is highly benefitted by drug delivery systems (DDS) designed to function with much higher specificity and lower side effects than the direct treatment with drugs. While many nanomaterials based DDS have been developed in the past few years to take advantage of the small size and high functionality of nanomaterials, silica-based nanomaterials have recently emerged as the flexible DDS with a high biocompatibility, good clearance, a high drug loading capacity, and versatility to attach several drugs and targeting agents to its surface. In this review, recent progress in the treatment of melanoma using silica-based nanomaterials and their hybrids is discussed, highlighting the versatility and potential of these emerging nanomaterials as the DDS for delivering various molecules, including drugs and immunotherapy agents, peptides, and radio- and photo-active agents. The review also introduces various therapies available for the treatment of melanoma, including surgery, chemotherapy, targeted therapy, phototherapy, and immunotherapy and discusses the improvement in these therapies based on silica-based DDS. The review also highlights the role of silica nanomaterials and their hybrids in delivering combination therapy and the advantages of silica nanohybrids over pure silica-based DDS. Finally, we summarize the present status of silica-based nanomaterials in melanoma treatment and the current challenges that have to be solved for the clinical translation of these materials as DDS.

The miniaturization and high integration of devices demand significant thermal management materials. Current technologies for the thermal management of electronics show some limitations in the case of multiple chip arrays. A device in multiple chip array is affected by heat from adjacent devices, along with thermal conductive composite. To address this problem, we present a nano composite of aligned boron nitride (BN) nanosheet islands with porous polydimethylsiloxane (PDMS) foam to have mechanical stability and non-thermal interference. The islands of tetrahedrally-structured BN in the composite have a high thermal conductivity of 1.219 W·m −1 ·K −1 in the through-plane direction (11.234 W·m −1 ·K −1 in the in-plane direction) with 16 wt.% loading of BN. On the other hand, porous PDMS foam has a low thermal conductivity of 0.0328 W·m −1 ·K −1 in the through-plane direction at 70% porosity. Heat pathways are then formed only in the structured BN islands of the composite. The porous PDMS foam can be applied as a thermal barrier between structured BN islands to inhibit thermal interference in multiple device arrays. Furthermore, this composite can maintain selective thermal dissipation performance with 70% tensile strain. Another beauty of the work is that it could have guided heat dissipation by assembling of multiple layers which have high vertical thermal conductive islands, while inhibiting thermal interference. The selective heat dissipating composite can be applied as a heatsink for multiple chip arrays electronics.

Developing a durable and efficient oxygen evolution reaction (OER) catalyst without noble metals is essential for the economical and sustainable production of hydrogen by alkaline water electrolysis. Recent studies have advocated triggering the lattice oxygen mechanism (LOM) to reduce the overpotential of catalysis and overcome the inherent limitations of the adsorbate evolution mechanism (AEM). Herein, we explored a facile and scalable method for synthesizing an iron‐rich nickel‐layered double hydroxide (NiFe‐LDH) with a unique hollow nanocapsule morphology using a metal‐organic framework (MOF) MIL‐88A as a sacrificial template for OER. The transformation of the MOF into hollow NiFe‐LDH provides abundant lattice oxygen defects and alters the Fermi level of O 2p, triggering LOM. As a result, the material exhibited outstanding OER performance, with a low overpotential of 244 mV at 10 mAcm −2 , and excellent long‐term durability. Ex‐situ X‐ray Photoelectron Spectroscopy (XPS) analysis of the catalyst before and after the OER reaction revealed a high density of surface oxygen defects in the Fe‐rich NiFe‐LDH, which is a prerequisite for LOM activation. Also, through in‐situ Raman spectroscopy, which monitored the appearance of superoxide intermediates (1040–1250 cm −1 ), revealed strong evidence for the involvement of the single metal site LOM and dual metal site LOM pathways in the OER. The presence of Fe 2+ and Fe 3+ in Fe‐rich NiFe‐LDH and the possible LOM mechanism were further evaluated using computational analyses.

A polyethylene vinyl acetic acid (EVA) nanocomposite comprising of an intumescent agent that incorporates ammonium phosphate monobasic, mono-pentaerythritol, and melamine with a cationic nanoclay was set up through solution blending and melt blending to assess the fire retardancy utilizing a cone calorimeter. The results demonstrated that there was a significant reduction in the peak heat release rate of 70% contrasted with pure EVA. The fire retardancy of the clay-organic intumescent mixture framework composite was more successful than a same amount of additional nanoclay and intumescent agent. To check these outcomes, the residues of cone calorimeter samples were assessed alongside clay d-spacing changes amid utilization.

The environmental issues associated with mining have damaged the industry’s substantial global economic value. In particular, the mining industry has a negative legacy of contaminated land. The effective reclamation of contaminated soil is therefore required before former mining land can be further developed for residential and commercial purposes. The objective of this study was to technically evaluate the feasibility of reclamation techniques for agricultural soils contaminated with toxic elements (As, Cd, Cu, Pb, and Zn) associated with metal mining. The reclamation methods investigated were covering without stabilization, covering with stabilization, and exchange with stabilization. The thickness of the soil layer used in covering and exchange was in the range of 30–50 cm. Limestone, furnace slag, and a mixture of limestone and furnace slag were applied as soil amendments. After reclamation, the contamination level in surface tillage soils and crops was monitored regularly. Four years of monitoring data revealed that surface soil contamination levels could be maintained at acceptable levels, although at some sites, the metal levels in crops exceeded legislative limits. Soil reclamation at former mining sites in Korea has not yet been perfected, but the results of this study show that there is potential for safe agricultural operations on large sites in a cost-effective manner, as long as the appropriate control of surface soil contamination and adequate agronomic management is undertaken.