Water splitting over Cu–Cu2O/TiO2 photocatalysts.

Selective release of hydrogen from formic acid (FA) is deemed feasible to solve issues associated with the production and storage of hydrogen. Here, we present a new efficient photocatalytic system consisting of CdS nanorods (NRs), Ni, and Co to liberate hydrogen from FA. The optimized noble-metal-free catalytic system employs Ni/Co as a redox mediator to relay electrons and holes from CdS NRs to the Ni and Co, respectively, which also deters the oxidation of CdS NRs. As a result, a high hydrogen production activity of 32.6 mmol h g from the decomposition of FA was noted. Furthermore, the photocatalytic system exhibits sustained H production rate for 12 h with sequential turnover numbers surpassing 4×10 , 3×10 , and 2×10 for Co-Ni/CdS NRs, Ni/CdS NRs, and CoCl /CdS NRs, respectively.

Graphitic-C3N4 is shown for the first time to catalyse photoacetalization of aldehydes/ketones with alcohols to acetals in high yields using visible light under ambient conditions; transient charge separation over the material is effective to catalyse the reaction in the absence of Lewis or Brønsted acids, giving a new green alternative catalyst.

No abstract

The development of an efficient, selective, and highly sensitive electrochemical sensor for the simultaneous analysis of multiple drugs is a tough challenge. Herein, we report an applied electrochemical sensing platform comprising both acid-and base-functionalized carbon nanotubes (CNTs) with zinc oxide nanoparticles between the layers (COOH-CNTs/ ZnO/NH 2 -CNTs) for the detection of paracetamol, diclofenac, and orphenadrine (PAR, DIC, and ORP) drugs with ultrahigh sensitivity and selectivity as evidenced by intense and well-resolved voltammetric signals. Prior to electrochemical analysis, the nanocomposite/ glassy carbon electrode (GCE) surface was characterized by multiple spectroscopic techniques. The performance of f CNTs/ZnO/f CNTs/GCE was probed by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and square-wave anodic stripping voltammetry (SWASV). The functionalized porous architecture with a large effective surface area provided a conduit for efficient mass transport and active sites for anchoring adsorbate molecules, thus leading to substantially lower oxidation overpotentials and amplified current signals. The f CNTs/ZnO/f CNTs/GCE exhibited a 6-fold increase in active surface area than bare GCE. Under optimized SWASV conditions, the designed sensor demonstrated simultaneous detection of PAR, DIC, and ORP with an unprecedented femtomolar limit of detection (46.8, 78, and 60 fM, respectively) within a time span of just 1 min. Besides the specificity, stability, and reliability studies of the designed sensing platform in multiple biological and pharmaceutical samples, % recoveries of 96−102% highlight the novelty and figures of merit of the designed electrochemical sensor. Moreover, computational studies were carried out that support the experimental outcome of a favorable charge transfer process between functional groups of the drugs and the sensor surface.

(2017) Structure-activity correlations for Brønsted acid, Lewis Acid, and photocatalyzed reactions of exfoliated crystalline niobium oxides. ChemCatChem, 9 (1). pp. 144-154.

No abstract

To investigate cost affordable and robust HER and OER catalysts with significant low overpotentials, we have successfully embedded fecoSe 2 spheres on smooth surfaces of graphitic carbon nitride that demonstrated high stability and electrocatalytic activity for H 2 production. We systematically analyzed the composition and morphology of fe x co 1−x Se 2 /g-c 3 n 4 and attributed the remarkable electrochemical performance of the catalyst to its unique structure. fe 0.2 co 0.8 Se 2 /g-c 3 n 4 showed a superior HER activity, with quite low overpotential value (83 mV at −20 mA cm −2 in 0.5 M H 2 So 4) and a current density of −3.24, −7.84, −14.80, −30.12 mA cm −2 at 0 V (vs RHE) in Dulbecco's Phosphate-Buffered Saline (DPBS), artificial sea water (ASW), 0.5 M H 2 So 4 and 1 M KOH, respectively. To the best of our knowledge, these are the highest reported current densities at this low potential value, showing intrinsic catalytic activity of the synthesized material. Also, the catalyst was found to deliver a high and stable current density of −1000 mA cm −2 at an overpotential of just 317 mV. Moreover, the synthesized catalyst delivered a constant current density of −30 mA cm −2 for 24 h without any noticeable change in potential at −0.2 V. These attributes confer our synthesized catalyst to be used for renewable fuel production and applications.