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In the field of biomemorizers, the simultaneous enhancement of resistive switching (RS) performance and environmental robustness, and the understanding the RS mechanism involving interfacial interaction is still challengeable. Herein, the bio-composites by encapsulating graphene (GR), graphene oxide (GO) and reduced graphene oxide (RGO) into chitosan (CS) have been fabricated as memory devices with the structure of FTO/bio-composite/Ag. Among them, FTO/GO@CS(12 %)/Ag biomemorizer exhibits the best RS performance with high ON/OFF ratio (105.92), and it possesses good thermal (170 °C) and irradiation stabilities (UV exposure for 96 h). The RS mechanism is due to the migration of oxygen vacancies accompanied by formation of Ag conducting filaments in the bio-composite films. Therefore, the enhanced resistive switching performance after encapsulating into CS can be explained as the increment of defects, the higher current densities and quenched radicals. Specially, for the first time we find the presence of voltage-induced packing mode changes in GO@CS composite, which can facilitate the migration of oxygen vacancies and render its best RS performance. In all, the more carboxyl groups can strengthen the GO-CS interfacial interactions through the formation of stable hydrogen bonding network and covalent bonds, which can enhance the stabilities and makes the composites be more sensitive to electrical stimulus. The rules drawn in this work will be significant for the construction of new biomemorizers with good environmental robustness. [Display omitted] • Graphene derivants (graphene, graphene oxide and reduced graphene oxide) have been encapsulated in chitosan to construct biomemorizers. • FTO/GO@CS (12 %)/Ag biomemorizer exhibited the good RS performance with high ON/OFF ratio and excellent thermal/irradiation stabilities. • The presence of voltage-induced packing mode changes in bio-composites can facilitate the migration of oxygen vacancies. • The more carboxyl groups can strengthen the GO-CS interfacial interactions, which can enhance the stabilities and makes the composites be more sensitive to electrical stimulus. [ABSTRACT FROM AUTHOR]

Bio-resistive memory devices with good environmental robustness are important for the next generation of biodegradable electronic devices. In this field, the facile achievement of both resistive switching performance and environmental robustness is still challengeable. Herein, resistive switching active oxidized multi-walled carbon nanotube (O-MWCNT) has been doped into chitosan (CS) to produce twisted O-MWCNT-CS biocomposites based on strong -COO-/NH 3 + electrostatic interaction. The FTO/O-MWCNT-CS(8%)/Ag biomemorizer can exhibit good resistive switching performance with high ON/OFF ratio (104.51) and low setting voltage (0.86 V). Besides, this biomemorizer possesses good environmental robustness with thermal (200 °C) and ionizing irradiation tolerance (UV exposure for 72 h). Ag conductive filament formation and rupture account for the resistive switching behavior. Specially, the conduction pathways provided by O-MWCNT and its good radical scavenging ability are the reason for the facile realization of resistive switching performances even under large layer thickness. The facile carboxylation on MWCNT and robust O-MWCNT-CS biocompoiste together with good environmental robustness render the promising applications as green, stable and biodegradable electronic devices. [Display omitted] • Oxidized multi-walled carbon nanotube was doped into chitosan to produce biocomposite with strong -COO-/NH 3 + interactions.. • The biomemorizer exhibits good resistive switching performance (ON/OFF ratio:104.51, V Set : 0.86 V). • This biomemorizer possesses good thermal/irradiating robustness (200 °C, UV exposure for 72 h). • The conduction pathways and radical scavenging ability account for the good resistive switching performances. [ABSTRACT FROM AUTHOR]

The searching for green memristor with good environmental robustness will be significant for next generation biodegradable devices. In this work, bio-compatible and non-toxic polydopamine (PDA) was prepared by self-polymerization of dopamine in simple aqueous solution, which was protonated by different acid concentrations (3–12 M HCl) and further fabricated as memory devices with structures of FTO/PDA/Ag. The ON/OFF ratio are enhanced gradually from 2.80 × 102 (PDA-3 M), 8.39 × 102 (PDA-6 M), 5.18 × 103 (PDA-9 M) to 2.41 × 104 (PDA-12 M). The lower conjugated degree, the closer lattice packing and the less radicals after acid treatment are the reasons for the enhanced bipolar resistive switching performances of protonated PDA-based memristor. The resistive switching mechanism is the conductive filament with three processes of Ohm, space charge limited conduction (SCLC) and trap-filled limited (TFL). In addition, the FTO/PDA-12 M/Ag exhibit good environmental robustness, including thermal (100 °C) and ionizing irradiation (UV exposure for 96 h). In all, the facial protonation treatment and the simple sandwich device structures together with good environmental robustness endow its promising applications in as green, stable and biodegradable next generation electron devices. The enhanced bipolar resistive switching performance and good environmental robustness can be achieved in protonated polydopamine based memristor, which is assigned to the lower conjugated degree, the closer lattice packing and the less radicals after acid treatment. [Display omitted] • Bio-compatible polydopamine was protonated by different acid concentrations and further fabricated as memory devices. • The reasons for the enhanced bipolar resistive switching performances of protonated PDA-based memristor was discussed. • The FTO/PDA-12 M/Ag exhibits good thermal (100 °C) and ionizing irradiation (UV exposure for 96 h) robustness. [ABSTRACT FROM AUTHOR]

• Memory devices fabricated with protonated g-C 3 N 4 can exhibit enhanced memory performances, in which acid concentration is crucial. • g-C3N4 treated with 8 M HCl presents the best resistive switching performance, which might be relative to its texture without violent tortuosity. • The protonated g-C 3 N 4 -based memory devices present good environmental robustness, including temperature and ionizing irradiation. • The high tolerant temperature (454 °C) can also be enhanced by doping BN for heat dissipation. Memory devices with simple sandwich structures using the g-C 3 N 4 treated by different concentration acids as active layers have been fabricated, which exhibit enhanced non-volatile bipolar switching performances and good environmental robustness. [Display omitted] The searching for new memory that can work under harsh conditions will be significant for their application in some important fields such as geothermal, oil and aerospace industries. In this work, memory devices with simple sandwich structures using the g-C 3 N 4 treated by different concentration acids as active layers have been fabricated, which exhibit non-volatile behaviors and bipolar switching characteristics. Protonation treatment can enhance the memory performance efficiently compared with un-protonized device. Among them, the device containing g-C 3 N 4 treated with 8 M HCl presents the best resistive switching performance with ON/OFF ratio of 104 and good retention capability, which might be relative to its texture without violent tortuosity. In addition, the protonated g-C 3 N 4 -based memory devices exhibit good environmental robustness, including temperature and ionizing irradiation. Specially, its high tolerant temperature (454 °C) can also be assisted by doping BN for heat dissipation. Their good thermal/irradiating stabilities are assigned to the strong bond energy of C N double bonds localized π-conjugated tri-s-triazine rings. In all, the facial protonation treatment without any functionalization or supporting, the simple sandwich device structure and good environmental robustness endow their promising applications in aerospace and outdoor environment. [ABSTRACT FROM AUTHOR]