Screen Printed Pb3O4 Films and Their Application to Photoresponsive and Photoelectrochemical Devices

Abstract

A new and simple procedure for the deposition of lead (II, IV) oxide films by screen printing was developed. In contrast to conventional electrochemical methods, films can be also deposited on non-conductive substrates without any specific dimensional restriction, being the only requirement the thermal stability of the substrate in air up to 500 °C to allow for the calcination of the screen printing paste and sintering of the film. In this study, films were exploited for the preparation of both photoresponsive devices and photoelectrochemical cell photoanodes. In both cases, screen printing was performed on FTO (Fluorine-Tin Oxide glass) substrates. The photoresponsive devices were tested with I-V curves in dark and under simulated solar light with different irradiation levels. Responses were evaluated at different voltage biases and under light pulses of different durations. Photoelectrochemical cells were tested by current density–voltage (J-V) curves under air mass (AM) 1.5 G illumination, incident photon-to-current efficiency (IPCE) measurements, and electrochemical impedance spectroscopy.

Pb/Pb3O4 Metal–Semiconductor Nanocomposite Obtained on 4A Zeolite─Optical and Structural Properties

“…Metallic nanoalloys containing metal oxides can enhance mechanical properties, thermal stability, electrical and magnetic characteristics, and corrosion resistance when compared to individual nanomaterials or their larger-scale counterparts. , These improvements enable a wide range of specific applications, especially in solar cells, biosensors, catalysis, and nanodevices, among others. − In addition, incorporating metal oxides can provide special electrical or magnetic properties to the alloys. − Lead and its oxides are mainly used to manufacture rechargeable lead-acid batteries, corrosion-resistant surface coatings, and catalysts. − In this context, photoconductive lead oxides have gained popularity as essential semiconductor materials in various optoelectronic devices. − Among the lead oxides, minimum or red lead (Pb 3 O 4 ) is a semiconductor with a band gap around 2.1–2.2 eV. It stands out due to its excellent pyroelectric and ferroelectric properties and high electrical resistivity .…”

“… 10 − 12 In this context, photoconductive lead oxides have gained popularity as essential semiconductor materials in various optoelectronic devices. 13 − 15 Among the lead oxides, minimum or red lead (Pb 3 O 4 ) is a semiconductor with a band gap around 2.1–2.2 eV. It stands out due to its excellent pyroelectric and ferroelectric properties and high electrical resistivity.…”

Chumbo e cádmio em unhas das mãos como biomarcadores de exposição subcrônica na biomonitorização de pré-escolares

“…As principais fontes de exposição ao chumbo para a população em geral, em especial para os pré-escolares, são: viver em ambiente urbano, principalmente em áreas próximas de fontes estacionárias do elemento (fábricas e indústrias metalúrgicas, de fundição, entre outras) e as áreas contaminadas geradas por essas fontes; o recobrimento de casas usando tintas contendo chumbo em sua composição e o contato com poeiras oriundas do desgaste dessas tintas; a alotriofagia (ato de consumir materiais não alimentícios); e as exposições ocupacionais secundárias (familiares de trabalhadores das fontes estacionárias) (BEAUCHEMIN et al, 2011;SANDERS et al, 2014;DIGNAM et al, 2018;OLYMPIO et al, 2018;HWANG et al, 2019;ATSDR, 2019.O principal uso dos compostos de chumbo é em baterias de chumbo ácido (ATSDR, 2019 (LIN et al, 2012;WHITE et al, 2013;GONZALEZ et al, 2017;PANETTA et al, 2018). A fonte de exposição de maior ocorrência se deve à deterioração de construções antigas, cujas paredes eram pintadas com tintas que continham chumbo sendo fontes potenciais de exposição ao elemento (SANDERS et al, 2014, NIH, 2018bSILVA et al, 2018).…”

“…O zarcão é um composto químico em pó de aparência alaranjada que era usado como revestimento anticorrosivo, protegendo materiais feitos de ferro da corrosão (OLYMPIO, 2018;PANETTA et al, 2018). Devido a essa propriedade, além de ser utilizado em tintas como pigmento, o zarcão pode ser aplicado também em materiais de ferro, tais como portões de residências e escolas (OLYMPIO et al, 2018;PANETTA et al, 2018). Além disso, em ambiente escolar, os pré-escolares também podem ser expostos a tintas à base de chumbo oriundas dos brinquedos de parquinhos das escolas (OLYMPIO et al, 2018;SILVA et al, 2018).…”