This review summarizes and discusses the recent progress in porous organic polymers for diverse biomedical applications such as drug delivery, biomacromolecule immobilization, phototherapy, biosensing, bioimaging, and antibacterial applications.

On the basis of the precise phase control of vanadium phosphorus oxides (VPOs), nanosized TiO 2 was employed as a dopant/dispersant to fabricate a series of VPO-TiO 2 catalysts through a wet mechanical co-milling process. The resulting catalysts showed outstanding durability plus excellent target products [acrylic acid (AA) + methyl acrylate (MA)] selectivity via acetic acid (HAc)−formaldehyde (FA) condensation. Over an optimized catalyst of 20% VPO-TiO 2 , the (AA + MA) selectivity being 85% (HAc input-based) at a yield level >60% (FA input-based) can be achieved after 180-h running, the best known to date over the VPObased catalysts. The detailed characterizations including X-ray powder diffraction, Raman spectra, XPS, and H 2 -TPR indicated that the V 5+ in the original VOPO 4 phase would be partially reduced in the presence of TiO 2 after the milling process in the cyclohexane medium; and the partially reduced VOPO 4 phase together with the decorated TiO 2 component stabilized the remaining V 5+ entities and considerably slowed down the continuous reduction of surface V 5+ species, accounting for substantially enhanced catalyst durability as well as target product selectivity. The NH 3 -/CO 2 -TPD results demonstrated that the surface acid−base property also varied notably with the VPO content which in turn controlled the HAc conversion and (MA + AA) selectivity accordingly.

A new type of supported vanadium phosphorus oxide (VPO) with self-phase regulation was simply fabricated (organic solvent free) for the first time by depositing the specific VPO precursor NH4(VO2)HPO4 onto the Siliceous Mesostructured Cellular Foams (MCF) with controlled activation. The resulting materials were found to be highly efficient and selective for sustainable acrylic acid (AA) plus methyl acrylate (MA) production via a condensation route between acetic acid (HAc) and formaldehyde (HCHO). A (AA + MA) yield of 83.7% (HCHO input-based) or a (AA + MA) selectivity of 81.7% (converted HAc-based) are achievable at 360 °C. The systematic characterizations and evaluations demonstrate a unique surface regulation occurring between the MCF and the NH4(VO2)HPO4 precursor. NH3 release upon activation of NH4(VO2)HPO4 precursor together with adsorption of NH3 by MCF automatically induces partial reduction of V5+ whose content is fine-tunable by the VPO loading. Such a functionalization simultaneously modifies phase constitution and surface acidity/basicity of catalyst, hence readily controls catalytic performance.

This study highlights the facet structure control of regular Ni x Co 3−x O 4 nanoplates and interfacial modulation through elemental doping and morphologically fitted assembly of Ti 3 C 2 T x nanosheets for high performances in OER/HER and overall water splitting. Over the resulting Ni 0.09 Co 2.91 O 4 /Ti 3 C 2 T x -HT in a solution of 1 M KOH, the OER and HER overpotentials of 262 and 210 mV, respectively, are achievable at a current density of 10 mA cm −2 . In the case of the overall water splitting by using Ni 0.09 Co 2.91 O 4 /Ti 3 C 2 T x -HT as anode and cathode catalysts, only a potential of 1.66 V is needed to obtain a current density of 10 mA cm −2 , and the catalysts can stand for a period of 70 h, remarkably outperforming the RuO 2 −Pt/C-based catalyst and benefiting from the intensive association and interfacial function between the Ti 3 C 2 T x and Ni x Co 3−x O 4 nanosheets. Interestingly, a surface reconstruction from the (112) to (111) facet structure occurred upon the fine-tuned Ni doping of regular Ni x Co 3−x O 4 hexagonal nanoplates and led to a highly active catalyst surface. At x = 0.09, the amount of Ni 3+ becomes the highest, which is favorable for the generation of the critical OH intermediates on Ni x Co 3−x O 4 /Ti 3 C 2 T x -HT. The current study documented the significance of the well-controlled interfacial assembly of transition-metal oxide/MXenes as an effective electrocatalyst in the OER/HER and overall water splitting processes and provided the insights into the structure−performance correlation over such kinds of precious metal-free catalysts.

In this study, we developed hierarchically structured Pt/SnO2/rGO electrocatalysts through a “layer-by-layer” synthetic strategy. Particularly, a morphologically controlled synthesis was adopted to obtain the regularly shaped SnO2 crystallites comprising the...

A series of unsupported and supported vanadium phosphorus oxide catalysts were prepared by employing a new strategy, which significantly reduced the complexity of catalyst preparation.

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N-doped TiO2 with oxygen vacancies exhibits many advantages for photocatalysis, such as enhanced visible light absorbency, inhibition of the photogenerated charge carrier recombination, etc. However, preparation of N-doped TiO2 with oxygen vacancies under mild conditions is still a challenge. Herein, N-doped TiO2 nanospheres with tetrahedral Ti4+ sites were synthesized by using dodecylamine as template and assisted by l-alanine acids. The obtained samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV–Vis diffuse reflectance spectra (UV–Vis DRS). It was found that the dodecylamine as a neutral surfactant controlled the structure of TiO2 spherical, while l-alanine acids provided a nitrogen source. The existence of tetrahedral Ti4+ sites in N-doped TiO2 was also confirmed. The N-doped TiO2 sample with tetrahedral Ti4+ sites exhibited significantly improved photocatalytic performance for degradation of methylene blue solution under UV light or visible light irradiation. A combined time-resolved infrared (IR) spectroscopy study reveals that the enhanced photocatalytic performance could be attributed to a large amount of photogenerated charge carriers and efficient charge separation. It is demonstrated that the shallow donor state produced by oxygen vacancies of tetrahedral Ti4+ sites can effectively promote separation of charge carriers besides capturing electrons.